All Publications

@article{aussieker2025,

title = {Ingestion of a Whey Plus Collagen Protein Blend Increases Myofibrillar and Muscle Connective Protein Synthesis Rates},

author = {Thorben Aussieker and Jeremias Kaiser and Wesley J H Hermans and Floris K Hendriks and Andrew M Holwerda and Joan M Senden and Janneau M X Kranenburg and Joy P B Goessens and Ulrike Braun and Keith Baar and Tim Snijders and Luc J C Loon},

doi = {10.1249/MSS.0000000000003596},

issn = {0195-9131},

year  = {2025},

date = {2025-03-01},

journal = {Medicine and Science in Sports and Exercise},

volume = {57},

number = {3},

pages = {544–554},

abstract = {Purpose: Ingestion of whey protein increases myofibrillar but not muscle connective protein synthesis rates. Recently, we defined a whey and collagen protein blend (5:1-ratio) to optimize post-prandial plasma amino acid availability. Here, we assessed the ability of this blend to increase myofibrillar and muscle connective protein synthesis rates at rest and during early recovery from exercise. Methods: In a randomized, double-blind, parallel design, 28 men (age: 25±5 y; BMI: 23.6±2.3 kg/m 2) were randomly allocated to ingest either 30 g of protein (25 g whey/5 g collagen; BLEND},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pinckaers2025,

title = {Oleuropein Supplementation Increases Resting Skeletal Muscle Fractional PDH Activity but Does Not Influence Whole-Body Metabolism: A Randomized, Double-Blind, Placebo-Controlled Trial in Healthy, Older Males},

author = {Philippe Jm Pinckaers and Heather L Petrick and Astrid Mh Horstman and Alba Moreno-Asso and Umberto De Marchi and Floris K Hendriks and Lisa Me Kuin and Cas J Fuchs and Dominik Grathwohl and Lex B Verdijk and Antoine H Zorenc and Joan Mg Senden and Eugenia Migliavacca and Sylviane Metairon and Laure Poquet and Delphine Morin-Rivron and Leonidas G Karagounis and Graham P Holloway and Jerome N Feige and Luc Jc Loon},

doi = {10.1016/j.tjnut.2025.02.015},

issn = {0022-3166},

year  = {2025},

date = {2025-02-01},

journal = {Journal of Nutrition},

abstract = {BACKGROUND: The polyphenol oleuropein activates mitochondrial calcium import, which increases pyruvate dehydrogenase (PDH) activity. Preclinically, this increase in PDH activity following oleuropein supplementation resulted in improved mitochondrial bioenergetics and fatigue resistance. OBJECTIVE: This study aimed to examine the effects of acute and chronic oleuropein supplementation on muscle energy metabolism, whole-body substrate metabolism, strength, and fatigue resistance in older males. METHODS: In a randomized, double-blind, placebo-controlled trial, 40 healthy older males (60±5y) received either placebo (PLA) or 100mg oleuropein from olive leaf extract (OLE) supplementation daily for 36 days. On day 1 and 36, muscle and blood samples were collected, and indirect calorimetry was performed, before and up to 120min following supplement intake. Leg strength and fatigue were measured before and after 29 days of supplementation. Results were analyzed using ANCOVA or robust ANCOVA. RESULTS: OLE ingestion on day 1 and 36 increased plasma oleuropein metabolites (P$<$0.001). On day 1, no differences were observed in muscle PDH activity, mitochondrial respiration, or whole-body substrate metabolism 120min after acute OLE ingestion. RNA sequencing revealed upregulation of oxidative phosphorylation gene pathways (FDR$<$0.05), while PDH-Ser -phosphorylation was higher after acute OLE vs PLA ingestion (P=0.015). Following chronic supplementation, fractional PDH activity was textasciitilde25% greater in OLE vs PLA (49±14 vs 38±10%; P=0.016) with no differences in absolute PDH activity and PDH-Ser -phosphorylation between groups. Mitochondrial respiration and protein content, whole-body substrate metabolism, leg strength and fatigue resistance, were not different between OLE vs PLA. Plasma LDL cholesterol was lower after chronic OLE vs PLA (P=0.043) with no differences in other blood metabolic markers. CONCLUSIONS: Chronic OLE supplementation resulted in higher skeletal muscle fractional PDH activity in healthy, older males, which may impact resting energy metabolism. Acute or chronic oleuropein supplementation do not modulate skeletal muscle mitochondrial respiration, muscle strength, muscle fatigue, or whole-body substrate metabolism. CLINICAL TRIAL REGISTRATION: Https://clinicaltrials.gov/study/NCT05217433. Registry: https://clinicaltrials.gov/study/NCT05217433.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{lim2025,

title = {Turning over New Ideas in Human Skeletal Muscle Proteostasis: What Do We Know and Where to from Here?},

author = {Changhyun Lim and James Mckendry and Matthew Lees and Philip J. Atherton and Nicholas A. Burd and Andrew M. Holwerda and Luc J. C. Loon and Chris Mcglory and Cameron J. Mitchell and Kenneth Smith and Daniel J. Wilkinson and Tanner Stokes and Stuart M. Phillips},

doi = {10.1113/EP092353},

issn = {0958-0670},

year  = {2025},

date = {2025-02-01},

journal = {Experimental Physiology},

number = {EP092353},

abstract = {Understanding the turnover of proteins in tissues gives information as to how external stimuli result in phenotypic change. Nowhere is such phenotypic change more conspicuous than skeletal muscle, which can be effectively remodelled by increased loading, ageing and unloading (disuse), all of which are subject to modification by nutrition and other environmental stimuli. The understanding of muscle proteome remodelling has undergone a renaissance recently with the reintroduction of deuterated water (D2O) and its ingestion to label amino acids and measure their incorporation into proteins. However, there is confusion around the use of the deuterated water methodology and the interpretation of the data it provides. Here, we provide a short review of some of the more salient features of the method and clarify some of the confusion around the method of deuterated water methods and its use in humans and how the interpretation of the data is in contrast to that of rodents.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{weijer2025,

title = {Measured and Predicted Resting Metabolic Rate of Dutch and Norwegian Paralympic Athletes},

author = {Vera C R Weijer and Kristin L Jonvik and Lotte Dam and Linn Risvang and Truls Raastad and Luc J C Loon and Jan-Willem Dijk},

doi = {10.1016/j.jand.2024.05.010},

issn = {2212-2672},

year  = {2025},

date = {2025-02-01},

journal = {Journal of the Academy of Nutrition and Dietetics},

volume = {125},

number = {2},

pages = {217-227.e5},

abstract = {Background: Although resting metabolic rate (RMR) is crucial for understanding athletes' energy requirements, limited information is available on the RMR of Paralympic athletes. Objective: The aim of this study was to determine RMR and its predictors in a diverse cohort of Paralympic athletes and evaluate the agreement between measured and predicted RMR from both newly developed and pre-existing equations. Design: This cross-sectional study, conducted between September 2020 and September 2022 in the Netherlands and Norway, assessed RMR in Paralympic athletes by means of ventilated hood indirect calorimetry and body composition by means of dual-energy x-ray absorptiometry. Participants: Sixty-seven Paralympic athletes (male: n = 37; female: n = 30) competing in various sports, with a spinal cord disorder (n = 22), neurologic condition (n = 8), limb deficiency (n = 18), visual or hearing impairment (n = 7), or other disability (n = 12) participated. Main outcome measures: RMR, fat-free mass (FFM), body mass, and triiodothyronine (T3) concentrations were assessed. Statistical analyses: Multiple regression analyses were conducted with height, FFM, body mass, sex, T3 concentration, and disabilities as potential predictors of RMR. Differences between measured and predicted RMRs were analyzed for individual accuracy, root mean square error, and intraclass correlation. Results: Mean ± SD RMR was 1386 ± 258 kcal/d for females and 1686 ± 302 kcal/d for males. Regression analysis identified FFM, T3 concentrations, and the presence of a spinal cord disorder, as the main predictors of RMR (adjusted R 2 = 0.71; F = 50.3; P $<$ .001). The novel prediction equations based on these data, as well as pre-existing equations of Chun and colleagues and Nightingale and Gorgey performed well on accuracy ($>$60% of participants within 10% of measured RMR), had good reliability (intraclass correlation $>$0.78), and low root mean square error ($łeq$141 kcal). Conclusions: FFM, total T3 concentrations, and presence of spinal cord disorder are the main predictors of RMR in Paralympic athletes. Both the current study's prediction equations and those from Chun and colleagues and Nightingale and Gorgey align well with measured RMR, offering accurate prediction equations for the RMR of Paralympic athletes.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{korzepa2025,

title = {Postprandial Plasma Amino Acid and Appetite Responses to a Low Protein Breakfast Supplemented with Whey or Pea Protein in Middle-to-Older Aged Adults},

author = {Marie Korzepa and Ryan N Marshall and Lucy M Rogers and Archie E Belfield and Jonathan I Quinlan and Yijia Huang and Ari Gritsas and Tyler A Churchward-Venne and Elisa I Glover and Luc J C Loon and Gareth A Wallis and Leigh Breen},

doi = {10.1007/s00394-025-03605-0},

issn = {1436-6207},

year  = {2025},

date = {2025-02-01},

journal = {European Journal of Nutrition},

volume = {64},

number = {2},

abstract = {The addition of low-dose protein to low protein-containing meals in middle-to-older aged adults may promote greater postprandial plasma aminoacidemia and mitigate declines in muscle health but may be dependent on the source and quality of protein consumed. This single-blind randomised study investigated postprandial plasma aminoacidemia and appetite regulatory responses to a typical lower protein-containing (textasciitilde0.07~g$cdot$kg body mass[BM] ) mixed breakfast supplemented with textasciitilde0.13~g$cdot$kg BM of whey protein concentrate (MB + WPC) or pea protein isolate (MB + PPI) in middle-to-older aged adults. Venous blood samples were collected whilst fasted and over a 180-min postprandial period to determine plasma amino acid and appetite hormone concentrations. Perceived appetite ratings were measured using Visual Analogue Scales. Plasma total amino acids and essential amino acids increased over time (both P $<$ 0.05) with no between-group differences or overall availability over 180~min (incremental area under the curve (iAUC)). Plasma leucine concentrations increased over time (both P $<$ 0.05) with greater peak concentrations (P = 0.032) and iAUC (P = 0.012) in MB + WPC compared with MB + PPI. Plasma total-ghrelin and total-GLP-1 concentrations and perceived ratings of hunger, fullness, and satiety were transiently altered following MB + WPC and MB + PPI (P $<$ 0.05 for all), with no differences between groups. In middle-to-older aged adults, co-ingesting a small bolus of whey protein alongside a typical lower protein-containing breakfast elicits greater plasma leucinemia than co-ingestion of pea protein, with no differential impact on appetite regulation. Whether the addition of low-dose whey protein to typical meals of middle-to-older aged adults can enhance muscle anabolism without adversely affecting appetite remains to be determined.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{vanlieshout2025,

title = {Protein Glycation Compromises the Bioavailability of Milk Protein-Derived Lysine in Vivo in Healthy Adult Males: A Double-Blind Randomized Cross-over Trial},

author = {Glenn Aa Lieshout and Jorn Trommelen and Jean Nyakayiru and Janneau Kranenburg and Joan M Senden and Annemie P Gijsen and Lex B Verdijk and Wilbert F Pellikaan and Marjolijn Ce Bragt and Luc Jc Loon},

doi = {10.1016/j.ajcnut.2025.01.025},

issn = {0002-9165},

year  = {2025},

date = {2025-01-01},

journal = {American Journal of Clinical Nutrition},

abstract = {BACKGROUND: Industrial processing and storage of milk products can strongly increase protein glycation level. Previously, we have reported that ingestion of highly glycated milk protein attenuates the post-prandial rise in plasma lysine concentrations when compared to the ingestion of an equivalent amount of milk protein with a low glycation level. Whether the attenuated increase in plasma lysine availability is attributed to compromised protein digestion and subsequent lysine absorption remains to be established. OBJECTIVE: The present study combined stable isotope methodology with the ingestion of, specifically produced, intrinsically labeled protein to assess protein digestion and amino acid absorption following ingestion of milk protein with a high versus low glycation level in vivo in humans. METHODS: 15 recreationally active, healthy young males participated in this double-blinded, randomized cross-over study. Subjects ingested 40 g intrinsically L-[1- C]-lysine-labeled milk protein with either a low (3%) or high (50%) glycation level. Continuous intravenous infusion of L-[4,4,5,5- H ]-lysine was combined with frequent blood sample collection during a 6-h post-prandial period to evaluate dietary protein-derived lysine release into the circulation. RESULTS: Post-prandial plasma lysine concentrations were lower following the ingestion of milk protein with a high versus low glycation level (time*treatment effect: P=0.002; ? =0.214), resulting in a 23 mmol$cdot$L $cdot$360 min [95%-CI:13-32] lower incremental area under the curve (0±12 vs 23±11 mmol$cdot$L $cdot$360 min , respectively, P$<$0.001). The post-prandial release of milk protein-derived lysine into the circulation was attenuated following ingestion of the protein with the high versus low glycation level (time*treatment effect: P$<$0.001; ? =0.640) and was 31% [95%-CI:26-36] lower over the full 6-h post-prandial period (18±4 vs 49±10% of the ingested lysine, respectively, P$<$0.001). CONCLUSIONS: A high level of milk protein glycation strongly reduces post-prandial plasma lysine availability in vivo in humans. Industrial processing and storage of (milk) protein products can strongly modulate protein bioavailability and, as such, lower the nutritional value of a protein source. This trial was registered at www. CLINICALTRIALS: gov as NCT05479916: https://clinicaltrials.gov/study/NCT05479916.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{fuchs2025,

title = {Repeated Passive Heat Treatment Increases Muscle Tissue Capillarization, but Does Not Affect Postprandial Muscle Protein Synthesis Rates in Healthy Older Adults},

author = {Cas J. Fuchs and Milan W. Betz and Heather L. Petrick and Jil Weber and Joan M. Senden and Floris K. Hendriks and Julia L. M. Bels and Luc J. C. Loon and Tim Snijders},

doi = {10.1113/JP286986},

issn = {0022-3751},

year  = {2025},

date = {2025-01-01},

journal = {Journal of Physiology},

volume = {603},

number = {1},

pages = {167–186},

abstract = {Abstract: Prolonged passive heat treatment (PHT) has been suggested to trigger skeletal muscle adaptations that may improve muscle maintenance in older individuals. To assess the effects of PHT on skeletal muscle tissue capillarization, perfusion capacity, protein synthesis rates, hypertrophy and leg strength, 14 older adults (9~males, 5 females; 73 ± 6~years) underwent 8~weeks of PHT (infrared sauna: 3× per week, 45~min at $sim$60$^circ$C). Before and after PHT we collected muscle biopsies to assess skeletal muscle capillarization and fibre cross-sectional area (CSA). Basal and postprandial muscle tissue perfusion kinetics and protein synthesis rates were assessed using contrast-enhanced ultrasound and primed continuous l-[ring- 13C 6]phenylalanine infusions, respectively. One-repetition maximum (1RM) leg strength and vastus lateralis muscle CSA were assessed. Type I and type II muscle fibre capillarization strongly increased following PHT (capillary-to-fibre perimeter exchange index: +31 ± 18 and +33 ± 30%, respectively; P~$<~$0.001). No changes were observed in basal (0.24 ± 0.27 vs. 0.18 ± 0.11 AU; P~=~0.266) or postprandial (0.20 ± 0.12 vs. 0.18 ± 0.14 AU; P~=~0.717) microvascular blood flow following PHT. Basal (0.048 ± 0.014 vs. 0.051 ± 0.019%/h; P~=~0.630) and postprandial (0.041 ± 0.012 vs. 0.051 ± 0.024%/h; P~=~0.199) muscle protein synthesis rates did not change in response to prolonged PHT. Furthermore, no changes in vastus lateralis muscle CSA (15.3 ± 4.6 vs. 15.2 ± 4.6 cm 2; P~=~0.768) or 1RM leg strength (46 ± 12 vs. 47 ± 12 kg; P~=~0.087) were observed over time. In conclusion, prolonged PHT increases muscle tissue capillarization but this does not improve muscle microvascular blood flow or increase muscle protein synthesis rates in healthy, older adults. Prolonged PHT does not induce skeletal muscle hypertrophy or increase leg strength in healthy, older adults. (Figure presented.). Key points: Repeated exposure to heat has been suggested to trigger skeletal muscle adaptive responses. We investigated the effect of 8~weeks of whole-body passive heat treatment (PHT; infrared sauna: 3× per week for 45~min at $sim$60$^circ$C) on skeletal muscle tissue capillarization, perfusion capacity, basal, and postprandial muscle protein synthesis rates, muscle (fibre) hypertrophy, and leg strength in healthy, older adults. Prolonged PHT increases muscle tissue capillarization, but this does not improve muscle microvascular blood flow or increase muscle protein synthesis rates. Despite increases in muscle tissue capillarization, prolonged PHT does not suffice to induce skeletal muscle hypertrophy or increase leg strength in healthy, older adults.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{aussieker2025a,

title = {Daily Blood Flow Restriction Does Not Affect Muscle Fiber Capillarization and Satellite Cell Content during 2 Wk of Bed Rest in Healthy Young Men},

author = {Thorben Aussieker and Cas J Fuchs and Antoine Zorenc and Lex B Verdijk and Luc J C Loon and Tim Snijders},

doi = {10.1152/japplphysiol.00461.2024},

issn = {8750-7587},

year  = {2025},

date = {2025-01-01},

journal = {Journal of Applied Physiology},

volume = {138},

number = {1},

pages = {89–98},

abstract = {The present study assessed whether single-leg daily blood flow restriction (BFR) treatment attenuates the decline in muscle fiber size, capillarization, and satellite cell (SC) content during 2 wk of bed rest in healthy, young men. Twelve healthy, young men (age: 24 ± 3 yr; BMI: 23.7 ± 3.1 kg/m 2) were subjected to 2 wk of bed rest, during which one leg was exposed to three times daily 5 min of BFR, whereas the contralateral leg received sham treatment [control (CON)]. Muscle biopsies were obtained from the m. vastus lateralis from both the BFR and CON legs before and immediately after 2 wk of bed rest. Types I and II muscle fiber size, myonuclear content, capillarization, and SC content were assessed by immunohistochemistry. No significant decline in either type I or type II muscle fiber size was observed following bed rest, with no differences between the CON and BFR legs (P $>$ 0.05). Type I muscle fiber capillary density increased in response to bed rest in both legs (P $<$ 0.05), whereas other muscle fiber capillarization measures remained unaltered. SC content decreased in both type I (from 7.4 ± 3.2 to 5.9 ± 2.7 per 100 fibers) and type II (from 7.2 ± 3.4 to 6.5 ± 3.2 per 100 fibers) muscle fibers (main effect of time P $frac14$ 0.018), with no significant differences between the BFR and CON legs (P $>$ 0.05). In conclusion, 2 wk of bed rest has no effect on muscle capillarization and decreases the SC content, and daily BFR treatment does not affect skeletal muscle fiber size and SC content in healthy, young men.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{weijer2024c,

title = {Continuous Glucose Monitoring in Para Cyclists: An Observational Study},

author = {Vera Weijer and Rob Werf and Myrthe Haijden and Asker Jeukendrup and Luc J. C. Loon and Jan-Willem Dijk},

doi = {10.1002/ejsc.12220},

issn = {1746-1391},

year  = {2024},

date = {2024-12-01},

journal = {European Journal of Sport Science},

volume = {24},

number = {12},

pages = {1809–1819},

abstract = {Continuous glucose monitoring (CGM) is an emerging tool for dietary counseling in athletes. This study aimed to explore blood glucose profiles in Para cyclists and evaluate CGM accuracy at rest and during exercise. Thirteen Para cyclists, comprising eight hand bikers and five cyclists, wore a CGM sensor (Abbott) for 2 weeks. Participants recorded the timing of meals and regular training sessions and executed one standardized training session. Fifteen capillary blood glucose reference values (seven at rest and eight during the standardized training) were obtained by finger pricks. Mean glucose concentrations and time spent in hypoglycemia ($<$3.9 mmol/L), euglycemia (3.9-7.8 mmol/L), and hyperglycemia ($>$7.8 mmol/L) were calculated over 24 hrs and during daytime, nighttime, exercise, and 2 hrs postprandial periods. Mean absolute relative differences (MARD) were calculated between the CGM and capillary blood glucose. The mean glucose concentration over the 24 hr-period was 5.7 (5.6-5.8) mmol/L. Athletes were in the euglycemia range 91% of the time. Hyperglycemia was almost exclusively observed postprandially and during exercise. Hypoglycemia was restricted to the night and was particularly observed in athletes with a spinal cord injury. CGM accuracy was acceptable at rest (MARD: 12%) but markedly lower during exercise (MARD: 34%; p = 0.01), especially for hand bikers (MARD: 41%) compared with cyclists (MARD: 24%; p = 0.01). Para cyclists generally do not display signs of disturbed glucose regulation. However, the increased risk for nocturnal hypoglycemia in athletes with a spinal cord injury warrants attention. Furthermore, CGM accuracy is compromised during exercise, especially if the sensor is in proximity to highly active muscles.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{houtvast2024a,

title = {Underpowered Studies in Muscle Metabolism Research: Determinants and Considerations},

author = {Dion C J Houtvast and Milan W Betz and Bas Van Hooren and Sophie Vanbelle and Lex B Verdijk and Luc J C Loon and Jorn Trommelen},

doi = {10.1016/j.clnesp.2024.10.152},

issn = {2405-4577},

year  = {2024},

date = {2024-12-01},

journal = {Clinical Nutrition ESPEN},

volume = {64},

pages = {334–343},

abstract = {Biomedical research frequently employs null hypothesis testing to determine whether an observed difference in a sample is likely to exist in the broader population. Null hypothesis testing generally assumes that differences between groups or interventions are non-existent, unless proven otherwise. Because biomedical studies with human subjects are often limited by financial and logistical resources, they tend to have low statistical power, i.e. a low probability of statistically confirming a true difference. As a result, small but potentially clinically important differences may be overseen or ignored simply due to the absence of a statistically significant difference. This absence is often misinterpreted as 'equivalence' of treatments. In this educational paper, we will use practical examples related to the effects of exercise and nutrition on muscle protein metabolism to illustrate the most important determinants of statistical power, as well as their implications for both investigators and readers of scientific articles. Changes in muscle mass occur at a relatively slow rate, making it practically challenging to detect differences between treatment groups in a long-term setting. One way to make it 'easier' to differentiate between groups and hence increase statistical power is to have a sufficiently long study duration to allow treatment effects to become apparent. This is especially relevant when comparing treatments with relatively small expected differences such as the effect of modest changes in daily protein intake. Secondly, one could try to minimize the variance and response heterogeneity within groups, for example by using strict inclusion criteria and standardization protocols (e.g., meal provision), by using cross-over designs, or even within-subject designs where two interventions are compared simultaneously (e.g., studying an exercised limb vs a contralateral control limb) although this might limit the generalizability of the findings (e.g. such single-limb exercise training is not common in practice). In terms of data interpretation, investigators should obviously refrain from drawing strong conclusions from underpowered studies. Yet, such studies still provide valuable data for meta-analyses. Finally, because muscle protein synthesis rates are highly responsive to anabolic stimuli, acute metabolic studies are more sensitive to detect potentially clinically relevant differences in the anabolic response between treatments. Apart from further elaborating on these topics, this educational article encourages readers to more critically question null findings and scientists to more clearly discuss limitations that may have compromised statistical power.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{domic2024a,

title = {A Well-Balanced Vegan Diet Does Not Compromise Daily Mixed Muscle Protein Synthesis Rates When Compared with an Omnivorous Diet in Active Older Adults: A Randomized Controlled Cross-Over Trial},

author = {Jacintha Domic and Philippe Jm Pinckaers and Pol Grootswagers and Els Siebelink and Johanna C Gerdessen and Luc Jc Loon and Lisette Cpgm Groot},

doi = {10.1016/j.tjnut.2024.12.019},

issn = {0022-3166},

year  = {2024},

date = {2024-12-01},

journal = {Journal of Nutrition},

abstract = {Background: Plant-based foods have reduced protein digestibility and frequently display unbalanced amino acid profiles. Plant-based foods are therefore considered inferior to animal-based foods in their anabolic potential. No study has assessed the anabolic potential of a vegan diet that provides a large variety of plant-based protein sources in older adults. Objectives: To investigate the effect of a 10-d vegan diet on daily mixed muscle protein synthesis (MPS) rates in comparison with an isocaloric, isonitrogenous, omnivorous diet in community-dwelling older adults. Methods: This cross-over trial assessed 34 community-dwelling older adults (72 ± 4 y, 18 males, 16 females), who were randomly assigned to consume a 10-d controlled vegan diet, followed by a controlled omnivorous diet (60% animal protein), or vice versa. One day before the study diets, participants consumed 400 mL deuterated water, followed by daily doses of 50 mL. Subsequent plasma and muscle samples were collected during the intervention period. Physical activity levels were assessed using accelerometry. Secondary outcomes were cardiometabolic risk factors and appetite. Statistical analyses were performed using linear mixed models, and results are presented as means ± standard errors. Results: Integrated MPS rates did not differ between the vegan (1.23 ± 0.04%/d) and omnivorous (1.29 ± 0.04%/d) diets (P = 0.2542). Plasma low-density lipoprotein (Δ0.23 ± 0.03, P $<$ 0.0001), high-density lipoprotein (Δ0.03 ± 0.14},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{weijer2024,

title = {Continuous Glucose Monitoring in Para Cyclists: An Observational Study},

author = {Vera Weijer and Rob Werf and Myrthe Haijden and Asker Jeukendrup and Luc J. C. Loon and Jan-Willem Dijk},

doi = {10.1002/ejsc.12220},

issn = {1746-1391},

year  = {2024},

date = {2024-12-01},

journal = {European Journal of Sport Science},

volume = {24},

number = {12},

pages = {1809–1819},

abstract = {Continuous glucose monitoring (CGM) is an emerging tool for dietary counseling in athletes. This study aimed to explore blood glucose profiles in Para cyclists and evaluate CGM accuracy at rest and during exercise. Thirteen Para cyclists, comprising eight hand bikers and five cyclists, wore a CGM sensor (Abbott) for 2 weeks. Participants recorded the timing of meals and regular training sessions and executed one standardized training session. Fifteen capillary blood glucose reference values (seven at rest and eight during the standardized training) were obtained by finger pricks. Mean glucose concentrations and time spent in hypoglycemia ($<$3.9 mmol/L), euglycemia (3.9-7.8 mmol/L), and hyperglycemia ($>$7.8 mmol/L) were calculated over 24 hrs and during daytime, nighttime, exercise, and 2 hrs postprandial periods. Mean absolute relative differences (MARD) were calculated between the CGM and capillary blood glucose. The mean glucose concentration over the 24 hr-period was 5.7 (5.6-5.8) mmol/L. Athletes were in the euglycemia range 91% of the time. Hyperglycemia was almost exclusively observed postprandially and during exercise. Hypoglycemia was restricted to the night and was particularly observed in athletes with a spinal cord injury. CGM accuracy was acceptable at rest (MARD: 12%) but markedly lower during exercise (MARD: 34%; p = 0.01), especially for hand bikers (MARD: 41%) compared with cyclists (MARD: 24%; p = 0.01). Para cyclists generally do not display signs of disturbed glucose regulation. However, the increased risk for nocturnal hypoglycemia in athletes with a spinal cord injury warrants attention. Furthermore, CGM accuracy is compromised during exercise, especially if the sensor is in proximity to highly active muscles.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{mezincescu2024,

title = {Comparison of Intramyocellular Lipid Metabolism in Patients with Diabetes and Male Athletes},

author = {Alice M. Mezincescu and Amelia Rudd and Lesley Cheyne and Graham Horgan and Sam Philip and Donnie Cameron and Luc Loon and Phil Whitfield and Rachael Gribbin and May Khei Hu and Mirela Delibegovic and Barbara Fielding and Gerald Lobley and Frank Thies and David E. Newby and Stuart Gray and Anke Henning and Dana Dawson},

doi = {10.1038/s41467-024-47843-y},

issn = {2041-1723},

year  = {2024},

date = {2024-12-01},

journal = {Nature Communications},

volume = {15},

number = {1},

abstract = {Despite opposing insulin sensitivity and cardiometabolic risk, both athletes and patients with type 2 diabetes have increased skeletal myocyte fat storage: the so-called ``athlete's paradox''. In a parallel non-randomised, non-blinded trial (NCT03065140), we characterised and compared the skeletal myocyte lipid signature of 29 male endurance athletes and 30 patients with diabetes after undergoing deconditioning or endurance training respectively. The primary outcomes were to assess intramyocellular lipid storage of the vastus lateralis in both cohorts and the secondary outcomes were to examine saturated and unsaturated intramyocellular lipid pool turnover. We show that athletes have higher intramyocellular fat saturation with very high palmitate kinetics, which is attenuated by deconditioning. In contrast, type 2 diabetes patients have higher unsaturated intramyocellular fat and blunted palmitate and linoleate kinetics but after endurance training, all were realigned with those of deconditioned athletes. Improved basal insulin sensitivity was further associated with better serum cholesterol/triglycerides, glycaemic control, physical performance, enhanced post insulin receptor pathway signalling and metabolic sensing. We conclude that insulin-resistant, maladapted intramyocellular lipid storage and turnover in patients with type 2 diabetes show reversibility after endurance training through increased contributions of the saturated intramyocellular fatty acid pools. Clinical Trial Registration: NCT03065140: Muscle Fat Compartments and Turnover as Determinant of Insulin Sensitivity (MISTY).},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{houtvast2024,

title = {Underpowered Studies in Muscle Metabolism Research: Determinants and Considerations},

author = {Dion C J Houtvast and Milan W Betz and Bas Van Hooren and Sophie Vanbelle and Lex B Verdijk and Luc J C Loon and Jorn Trommelen},

doi = {10.1016/j.clnesp.2024.10.152},

issn = {2405-4577},

year  = {2024},

date = {2024-12-01},

journal = {Clinical Nutrition ESPEN},

volume = {64},

pages = {334–343},

abstract = {Biomedical research frequently employs null hypothesis testing to determine whether an observed difference in a sample is likely to exist in the broader population. Null hypothesis testing generally assumes that differences between groups or interventions are non-existent, unless proven otherwise. Because biomedical studies with human subjects are often limited by financial and logistical resources, they tend to have low statistical power, i.e. a low probability of statistically confirming a true difference. As a result, small but potentially clinically important differences may be overseen or ignored simply due to the absence of a statistically significant difference. This absence is often misinterpreted as 'equivalence' of treatments. In this educational paper, we will use practical examples related to the effects of exercise and nutrition on muscle protein metabolism to illustrate the most important determinants of statistical power, as well as their implications for both investigators and readers of scientific articles. Changes in muscle mass occur at a relatively slow rate, making it practically challenging to detect differences between treatment groups in a long-term setting. One way to make it 'easier' to differentiate between groups and hence increase statistical power is to have a sufficiently long study duration to allow treatment effects to become apparent. This is especially relevant when comparing treatments with relatively small expected differences such as the effect of modest changes in daily protein intake. Secondly, one could try to minimize the variance and response heterogeneity within groups, for example by using strict inclusion criteria and standardization protocols (e.g., meal provision), by using cross-over designs, or even within-subject designs where two interventions are compared simultaneously (e.g., studying an exercised limb vs a contralateral control limb) although this might limit the generalizability of the findings (e.g. such single-limb exercise training is not common in practice). In terms of data interpretation, investigators should obviously refrain from drawing strong conclusions from underpowered studies. Yet, such studies still provide valuable data for meta-analyses. Finally, because muscle protein synthesis rates are highly responsive to anabolic stimuli, acute metabolic studies are more sensitive to detect potentially clinically relevant differences in the anabolic response between treatments. Apart from further elaborating on these topics, this educational article encourages readers to more critically question null findings and scientists to more clearly discuss limitations that may have compromised statistical power.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{domic2024,

title = {A Well-Balanced Vegan Diet Does Not Compromise Daily Mixed Muscle Protein Synthesis Rates When Compared with an Omnivorous Diet in Active Older Adults: A Randomized Controlled Cross-Over Trial},

author = {Jacintha Domic and Philippe Jm Pinckaers and Pol Grootswagers and Els Siebelink and Johanna C Gerdessen and Luc Jc Loon and Lisette Cpgm Groot},

doi = {10.1016/j.tjnut.2024.12.019},

issn = {0022-3166},

year  = {2024},

date = {2024-12-01},

journal = {Journal of Nutrition},

abstract = {Background: Plant-based foods have reduced protein digestibility and frequently display unbalanced amino acid profiles. Plant-based foods are therefore considered inferior to animal-based foods in their anabolic potential. No study has assessed the anabolic potential of a vegan diet that provides a large variety of plant-based protein sources in older adults. Objectives: To investigate the effect of a 10-d vegan diet on daily mixed muscle protein synthesis (MPS) rates in comparison with an isocaloric, isonitrogenous, omnivorous diet in community-dwelling older adults. Methods: This cross-over trial assessed 34 community-dwelling older adults (72 ± 4 y, 18 males, 16 females), who were randomly assigned to consume a 10-d controlled vegan diet, followed by a controlled omnivorous diet (60% animal protein), or vice versa. One day before the study diets, participants consumed 400 mL deuterated water, followed by daily doses of 50 mL. Subsequent plasma and muscle samples were collected during the intervention period. Physical activity levels were assessed using accelerometry. Secondary outcomes were cardiometabolic risk factors and appetite. Statistical analyses were performed using linear mixed models, and results are presented as means ± standard errors. Results: Integrated MPS rates did not differ between the vegan (1.23 ± 0.04%/d) and omnivorous (1.29 ± 0.04%/d) diets (P = 0.2542). Plasma low-density lipoprotein (Δ0.23 ± 0.03, P $<$ 0.0001), high-density lipoprotein (Δ0.03 ± 0.14},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{kouw2024a,

title = {Short-Term Intermittent Fasting and Energy Restriction Do Not Impair Rates of Muscle Protein Synthesis: A Randomised, Controlled Dietary Intervention},

author = {Imre W. K. Kouw and Evelyn B. Parr and Michael J. Wheeler and Bridget E. Radford and Rebecca C. Hall and Joan M. Senden and Joy P. B. Goessens and Luc J. C. Loon and John A. Hawley},

doi = {10.1016/j.clnu.2024.09.034},

issn = {0261-5614},

year  = {2024},

date = {2024-11-01},

journal = {Clinical Nutrition},

volume = {43},

number = {11},

pages = {174–184},

abstract = {Background: Intermittent fasting (IF) is an effective energy restricted dietary strategy to reduce body and fat mass and improve metabolic health in individuals with either an overweight or obese status. However, dietary energy restriction may impair muscle protein synthesis (MPS) resulting in a concomitant decline in lean body mass. Due to periods of prolonged fasting combined with irregular meal intake, we hypothesised that IF would reduce rates of MPS compared to an energy balanced diet with regular meal patterns. Aims: We assessed the impact of a short-term, ten days, alternate day fasting or a continuous energy restricted diet to a control diet on integrated rates of skeletal MPS in middle-aged males with overweight or obesity. Methods: Twenty-seven middle-aged males with overweight or obesity (age: 44.6 ± 5.4 y; BMI: 30.3 ± 2.6 kg/m2) consumed a three-day lead-in diet, followed by a ten-day controlled dietary intervention matched for protein intake, as alternate day fasting (ADF: 62.5 energy (En)%, days of 25 En% alternated with days of 100 En% food ingestion), continuous energy restriction (CER: 62.5 En%), or an energy balanced, control diet (CON: 100 En%). Deuterated water (D2O) methodology with saliva, blood, and skeletal muscle sampling were used to assess integrated rates of MPS over the ten-day intervention period. Secondary measures included fasting plasma glucose, insulin, and gastrointestinal hormone concentrations, continuous glucose monitoring, and assessment of body composition. Results: There were no differences in daily rates of MPS between groups (ADF: 1.18 ± 0.13, CER: 1.13 ± 0.16, and CON: 1.18 ± 0.18 %/day, P $>$ 0.05). The reductions in body mass were greater in ADF and CER compared to CON (P $<$ 0.001). Lean and fat mass were decreased by a similar magnitude across groups (main time effect, P $<$ 0.001; main group effect, P $>$ 0.05). Fasting plasma leptin concentrations decreased in ADF and CER (P $<$ 0.001), with no differences in fasting plasma glucose or insulin concentrations between groups. Conclusion: Short-term alternate day fasting does not lower rates of MPS compared to continuous energy restriction or an energy balanced, control diet with matched protein intake. The prolonged effects of IF and periods of irregular energy and protein intake patterns on muscle mass maintenance remain to be investigated. This trial was registered under Australian New Zealand Clinical Trial Registry (https://www.anzctr.org.au), identifier no. ACTRN12619000757112.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{holwerda2024c,

title = {Assessing Muscle Protein Synthesis Rates in Vivo in Humans: The Deuterated Water (2H2O) Method},

author = {Andrew M Holwerda and Philip J Atherton and Kenneth Smith and Daniel J Wilkinson and Stuart M Phillips and Luc J C Loon},

doi = {10.1016/j.tjnut.2024.09.012},

issn = {0022-3166},

year  = {2024},

date = {2024-11-01},

journal = {Journal of Nutrition},

volume = {154},

number = {11},

pages = {3177–3189},

abstract = {Skeletal muscle tissue is in a constant state of turnover, with muscle tissue protein synthesis and breakdown rates ranging between 1% and 2% across the day in vivo in humans. Muscle tissue remodeling is largely controlled by the up- and down-regulation of muscle tissue protein synthesis rates. Research studies generally apply stable isotope-labeled amino acids to assess muscle protein synthesis rates in vivo in humans. Following labeled amino acid administration in a laboratory setting, muscle tissue samples are collected over several hours to assess the incorporation rate of these labeled amino acids in muscle tissue protein. To allow quantification of bulk muscle protein synthesis rates over more prolonged periods, the use of deuterated water methodology has regained much interest. Ingestion of daily boluses of deuterium oxide results in 2H enrichment of the body water pool. The available 2H-atoms become incorporated into endogenously synthesized alanine primarily through transamination of pyruvate in the liver. With 2H-alanine widely available to all tissues, it becomes incorporated into de novo synthesized tissue proteins. Assessing the increase in tissue protein-bound 2H-alanine enrichment in muscle biopsy samples over time allows for the calculation of muscle protein synthesis rates over several days or even weeks. As the deuterated water method allows for the assessment of muscle tissue protein synthesis rates under free-living conditions in nonlaboratory settings, there is an increasing interest in its application. This manuscript describes the theoretical background of the deuterated water method and offers a comprehensive tutorial to correctly apply the method to determine bulk muscle protein synthesis rates in vivo in humans.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{kouw2024,

title = {Short-Term Intermittent Fasting and Energy Restriction Do Not Impair Rates of Muscle Protein Synthesis: A Randomised, Controlled Dietary Intervention},

author = {Imre W. K. Kouw and Evelyn B. Parr and Michael J. Wheeler and Bridget E. Radford and Rebecca C. Hall and Joan M. Senden and Joy P. B. Goessens and Luc J. C. Loon and John A. Hawley},

doi = {10.1016/j.clnu.2024.09.034},

issn = {0261-5614},

year  = {2024},

date = {2024-11-01},

journal = {Clinical Nutrition},

volume = {43},

number = {11},

pages = {174–184},

abstract = {Background: Intermittent fasting (IF) is an effective energy restricted dietary strategy to reduce body and fat mass and improve metabolic health in individuals with either an overweight or obese status. However, dietary energy restriction may impair muscle protein synthesis (MPS) resulting in a concomitant decline in lean body mass. Due to periods of prolonged fasting combined with irregular meal intake, we hypothesised that IF would reduce rates of MPS compared to an energy balanced diet with regular meal patterns. Aims: We assessed the impact of a short-term, ten days, alternate day fasting or a continuous energy restricted diet to a control diet on integrated rates of skeletal MPS in middle-aged males with overweight or obesity. Methods: Twenty-seven middle-aged males with overweight or obesity (age: 44.6 ± 5.4 y; BMI: 30.3 ± 2.6 kg/m2) consumed a three-day lead-in diet, followed by a ten-day controlled dietary intervention matched for protein intake, as alternate day fasting (ADF: 62.5 energy (En)%, days of 25 En% alternated with days of 100 En% food ingestion), continuous energy restriction (CER: 62.5 En%), or an energy balanced, control diet (CON: 100 En%). Deuterated water (D2O) methodology with saliva, blood, and skeletal muscle sampling were used to assess integrated rates of MPS over the ten-day intervention period. Secondary measures included fasting plasma glucose, insulin, and gastrointestinal hormone concentrations, continuous glucose monitoring, and assessment of body composition. Results: There were no differences in daily rates of MPS between groups (ADF: 1.18 ± 0.13, CER: 1.13 ± 0.16, and CON: 1.18 ± 0.18 %/day, P $>$ 0.05). The reductions in body mass were greater in ADF and CER compared to CON (P $<$ 0.001). Lean and fat mass were decreased by a similar magnitude across groups (main time effect, P $<$ 0.001; main group effect, P $>$ 0.05). Fasting plasma leptin concentrations decreased in ADF and CER (P $<$ 0.001), with no differences in fasting plasma glucose or insulin concentrations between groups. Conclusion: Short-term alternate day fasting does not lower rates of MPS compared to continuous energy restriction or an energy balanced, control diet with matched protein intake. The prolonged effects of IF and periods of irregular energy and protein intake patterns on muscle mass maintenance remain to be investigated. This trial was registered under Australian New Zealand Clinical Trial Registry (https://www.anzctr.org.au), identifier no. ACTRN12619000757112.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{holwerda2024b,

title = {Assessing Muscle Protein Synthesis Rates in Vivo in Humans: The Deuterated Water (2H2O) Method},

author = {Andrew M Holwerda and Philip J Atherton and Kenneth Smith and Daniel J Wilkinson and Stuart M Phillips and Luc J C Loon},

doi = {10.1016/j.tjnut.2024.09.012},

issn = {0022-3166},

year  = {2024},

date = {2024-11-01},

journal = {Journal of Nutrition},

volume = {154},

number = {11},

pages = {3177–3189},

abstract = {Skeletal muscle tissue is in a constant state of turnover, with muscle tissue protein synthesis and breakdown rates ranging between 1% and 2% across the day in vivo in humans. Muscle tissue remodeling is largely controlled by the up- and down-regulation of muscle tissue protein synthesis rates. Research studies generally apply stable isotope-labeled amino acids to assess muscle protein synthesis rates in vivo in humans. Following labeled amino acid administration in a laboratory setting, muscle tissue samples are collected over several hours to assess the incorporation rate of these labeled amino acids in muscle tissue protein. To allow quantification of bulk muscle protein synthesis rates over more prolonged periods, the use of deuterated water methodology has regained much interest. Ingestion of daily boluses of deuterium oxide results in 2H enrichment of the body water pool. The available 2H-atoms become incorporated into endogenously synthesized alanine primarily through transamination of pyruvate in the liver. With 2H-alanine widely available to all tissues, it becomes incorporated into de novo synthesized tissue proteins. Assessing the increase in tissue protein-bound 2H-alanine enrichment in muscle biopsy samples over time allows for the calculation of muscle protein synthesis rates over several days or even weeks. As the deuterated water method allows for the assessment of muscle tissue protein synthesis rates under free-living conditions in nonlaboratory settings, there is an increasing interest in its application. This manuscript describes the theoretical background of the deuterated water method and offers a comprehensive tutorial to correctly apply the method to determine bulk muscle protein synthesis rates in vivo in humans.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{betz2024b,

title = {Muscle Fibre Satellite Cells Are Located at a Greater Distance from Capillaries in Patients with COPD Compared with Healthy Controls},

author = {Milan W Betz and Jana De Brandt and Thorben Aussieker and Alejandra P Monsegue and Dion C J Houtvast and Sebastian Gehlert and Lex B Verdijk and Luc J C Loon and Harry R Gosker and Ramon J C Langen and Wim Derave and Chris Burtin and Martijn A Spruit and Tim Snijders},

doi = {10.1183/23120541.00203-2024},

issn = {2312-0541},

year  = {2024},

date = {2024-09-01},

journal = {ERJ Open Research},

volume = {10},

number = {5},

abstract = {Background COPD is a disease characterised by skeletal muscle dysfunction. A spatial relationship exists between satellite cells and muscle fibre capillaries, which has been suggested to be of major importance for satellite cell function. In the present study we compared the spatial relationship between satellite cells and capillaries in patients with COPD and age-matched healthy older adults. Methods Muscle biopsies were obtained from the vastus lateralis of n=18 patients with COPD (8 female, 10 male; age 66±5 years, mild-to-severe airflow obstruction) and n=18 age-, sex-and body mass index-matched healthy control adults (8 female, 10 male; age 68±5 years). Immunohistochemistry was used to assess type I/II muscle fibre size, distribution, myonuclear content, satellite cell number and fibre capillarisation. In addition, type I/II muscle fibre satellite cell distance to its nearest capillary was assessed. Results The percentage of type II muscle fibres was significantly greater in patients with COPD (62±10%) compared with controls (50±12%, p$<$0.05). Muscle fibre capillarisation was significantly lower in patients with COPD compared with controls (p$<$0.05). While satellite cell content was not different between groups, type I and type II satellite cell distance to its nearest capillary was significantly greater in patients with COPD (type I: 21.3±4.8 µm; type II: 26.7±9.3 µm) compared with controls (type I: 16.1±3.5 µm; type II: 22.7±5.8 µm; p$<$0.05). Conclusion Satellite cells are located at a greater distance from their nearest capillary in patients with COPD compared with age-matched controls. This increased distance could play a role in impaired satellite cell function in patients with COPD.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{betz2024a,

title = {Muscle Fibre Satellite Cells Are Located at a Greater Distance from Capillaries in Patients with COPD Compared with Healthy Controls},

author = {Milan W Betz and Jana De Brandt and Thorben Aussieker and Alejandra P Monsegue and Dion C J Houtvast and Sebastian Gehlert and Lex B Verdijk and Luc J C Loon and Harry R Gosker and Ramon J C Langen and Wim Derave and Chris Burtin and Martijn A Spruit and Tim Snijders},

doi = {10.1183/23120541.00203-2024},

issn = {2312-0541},

year  = {2024},

date = {2024-09-01},

journal = {ERJ Open Research},

volume = {10},

number = {5},

abstract = {Background COPD is a disease characterised by skeletal muscle dysfunction. A spatial relationship exists between satellite cells and muscle fibre capillaries, which has been suggested to be of major importance for satellite cell function. In the present study we compared the spatial relationship between satellite cells and capillaries in patients with COPD and age-matched healthy older adults. Methods Muscle biopsies were obtained from the vastus lateralis of n=18 patients with COPD (8 female, 10 male; age 66±5 years, mild-to-severe airflow obstruction) and n=18 age-, sex-and body mass index-matched healthy control adults (8 female, 10 male; age 68±5 years). Immunohistochemistry was used to assess type I/II muscle fibre size, distribution, myonuclear content, satellite cell number and fibre capillarisation. In addition, type I/II muscle fibre satellite cell distance to its nearest capillary was assessed. Results The percentage of type II muscle fibres was significantly greater in patients with COPD (62±10%) compared with controls (50±12%, p$<$0.05). Muscle fibre capillarisation was significantly lower in patients with COPD compared with controls (p$<$0.05). While satellite cell content was not different between groups, type I and type II satellite cell distance to its nearest capillary was significantly greater in patients with COPD (type I: 21.3±4.8 µm; type II: 26.7±9.3 µm) compared with controls (type I: 16.1±3.5 µm; type II: 22.7±5.8 µm; p$<$0.05). Conclusion Satellite cells are located at a greater distance from their nearest capillary in patients with COPD compared with age-matched controls. This increased distance could play a role in impaired satellite cell function in patients with COPD.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{schenaarts2024a,

title = {A Single Sauna Session Does Not Improve Postprandial Blood Glucose Handling in Individuals with Type 2 Diabetes Mellitus: A Cross-over, Randomized, Controlled Trial},

author = {Laura Schenaarts and Floris K Hendriks and Cas J Fuchs and Wendy Em Sluijsmans and Tim Snijders and Luc Jc Loon},

doi = {10.1055/a-2406-4491},

issn = {1439-3646},

year  = {2024},

date = {2024-08-01},

journal = {Experimental and clinical endocrinology & diabetes},

abstract = {INTRODUCTION: Passive heat treatment has been suggested to improve glycaemic control in individuals with type 2 diabetes mellitus. Previous studies have predominantly focused on hot water immersion and traditional sauna bathing, as opposed to the more novel method of infrared-based sauna bathing. Here we assessed the impact of a single infrared sauna session on post-prandial glycaemic control in older individuals with type 2 diabetes mellitus. METHODS: In this randomized controlled crossover trial, 12 participants with type 2 diabetes mellitus (male/female: 10/2, age: 69±7 y, BMI: 27.5±2.9 kg/m ) rested in an infrared sauna twice: once in a heated condition (60$^circ$C) and once in a thermoneutral condition (21$^circ$C) for 40 min, immediately followed by a 2-h oral glucose tolerance test (OGTT). Venous blood samples were obtained to assess plasma glucose and insulin concentrations and to determine the whole-body composite insulin sensitivity index. RESULTS: Body core and leg skin temperature were higher following the heated condition compared to the thermoneutral condition (38.0±0.3 vs 36.6±0.2$^circ$C and 39.4±0.8 vs 31.3±0.8$^circ$C, respectively; $<$0.001 for both). The incremental area under the curve (iAUC) of plasma glucose concentrations during the OGTT was higher after the heated condition compared to the thermoneutral condition (17.7±3.1 vs 14.8±2.8 mmol/L/120 min; $<$0.001). No differences were observed in plasma insulin concentrations (heated: 380±194 vs thermoneutral: 376±210 pmol/L/120 min; =0.93) or whole-body composite insulin sensitivity indexes (4.5±2.8 vs 4.5±2.1; =0.67). A single infrared sauna session does not improve postprandial blood glucose handling in individuals with type 2 diabetes mellitus. Future studies should assess the effect of more prolonged application of infrared sauna bathing on daily glycaemic control.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{weijzen2024,

title = {Reply - Letter to the Editor: Access to a Pre-Sleep Protein Snack Increases Daily Energy and Protein Intake in Surgical Hospitalized Patients},

author = {Michelle E. G. Weijzen and Luc J. C. Loon},

doi = {10.1016/j.clnu.2024.06.032},

issn = {0261-5614},

year  = {2024},

date = {2024-08-01},

journal = {Clinical Nutrition},

volume = {43},

number = {8},

pages = {1888–1889},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{schenaarts2024,

title = {A Single Sauna Session Does Not Improve Postprandial Blood Glucose Handling in Individuals with Type 2 Diabetes Mellitus: A Cross-over, Randomized, Controlled Trial},

author = {Laura Schenaarts and Floris K Hendriks and Cas J Fuchs and Wendy Em Sluijsmans and Tim Snijders and Luc Jc Loon},

doi = {10.1055/a-2406-4491},

issn = {1439-3646},

year  = {2024},

date = {2024-08-01},

journal = {Experimental and clinical endocrinology & diabetes},

abstract = {INTRODUCTION: Passive heat treatment has been suggested to improve glycaemic control in individuals with type 2 diabetes mellitus. Previous studies have predominantly focused on hot water immersion and traditional sauna bathing, as opposed to the more novel method of infrared-based sauna bathing. Here we assessed the impact of a single infrared sauna session on post-prandial glycaemic control in older individuals with type 2 diabetes mellitus. METHODS: In this randomized controlled crossover trial, 12 participants with type 2 diabetes mellitus (male/female: 10/2, age: 69±7 y, BMI: 27.5±2.9 kg/m ) rested in an infrared sauna twice: once in a heated condition (60$^circ$C) and once in a thermoneutral condition (21$^circ$C) for 40 min, immediately followed by a 2-h oral glucose tolerance test (OGTT). Venous blood samples were obtained to assess plasma glucose and insulin concentrations and to determine the whole-body composite insulin sensitivity index. RESULTS: Body core and leg skin temperature were higher following the heated condition compared to the thermoneutral condition (38.0±0.3 vs 36.6±0.2$^circ$C and 39.4±0.8 vs 31.3±0.8$^circ$C, respectively; $<$0.001 for both). The incremental area under the curve (iAUC) of plasma glucose concentrations during the OGTT was higher after the heated condition compared to the thermoneutral condition (17.7±3.1 vs 14.8±2.8 mmol/L/120 min; $<$0.001). No differences were observed in plasma insulin concentrations (heated: 380±194 vs thermoneutral: 376±210 pmol/L/120 min; =0.93) or whole-body composite insulin sensitivity indexes (4.5±2.8 vs 4.5±2.1; =0.67). A single infrared sauna session does not improve postprandial blood glucose handling in individuals with type 2 diabetes mellitus. Future studies should assess the effect of more prolonged application of infrared sauna bathing on daily glycaemic control.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{hengist2024,

title = {Ketogenic Diet but Not Free-Sugar Restriction Alters Glucose Tolerance, Lipid Metabolism, Peripheral Tissue Phenotype, and Gut Microbiome: RCT},

author = {Aaron Hengist and Russell G Davies and Jean-Philippe Walhin and Jariya Buniam and Lucy H Merrell and Lucy Rogers and Louise Bradshaw and Alfonso Moreno-Cabañas and Peter J Rogers and Jeff M Brunstrom and Leanne Hodson and Luc J C Loon and Wiley Barton and Ciara O'Donovan and Fiona Crispie and Orla O'Sullivan and Paul D Cotter and Kathryn Proctor and James A Betts and Françoise Koumanov and Dylan Thompson and Javier T Gonzalez},

doi = {10.1016/j.xcrm.2024.101667},

issn = {2666-3791},

year  = {2024},

date = {2024-08-01},

journal = {Cell Reports Medicine},

number = {101667},

abstract = {Restricted sugar and ketogenic diets can alter energy balance/metabolism, but decreased energy intake may be compensated by reduced expenditure. In healthy adults, randomization to restricting free sugars or overall carbohydrates (ketogenic diet) for 12~weeks reduces fat mass without changing energy expenditure versus control. Free-sugar restriction minimally affects metabolism or gut microbiome but decreases low-density lipoprotein cholesterol (LDL-C). In contrast, a ketogenic diet decreases glucose tolerance, increases skeletal muscle PDK4, and reduces AMPK and GLUT4 levels. By week 4, the ketogenic diet reduces fasting glucose and increases apolipoprotein B, C-reactive protein, and postprandial glycerol concentrations. However, despite sustained ketosis, these effects are no longer apparent by week 12, when gut microbial beta diversity is altered, possibly reflective of longer-term adjustments to the ketogenic diet and/or energy balance. These data demonstrate that restricting free sugars or overall carbohydrates reduces energy intake without altering physical activity, but with divergent effects on glucose tolerance, lipoprotein profiles, and gut microbiome.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{trommelen2024a,

title = {Protein Intake Distribution: Beneficial, Detrimental, or Inconsequential for Muscle Anabolism? Response to Witard & Mettler},

author = {Jorn Trommelen and Andrew M Holwerda and Luc J C Loon},

doi = {10.1123/ijsnem.2024-0107},

issn = {1526-484X},

year  = {2024},

date = {2024-07-01},

journal = {International Journal of Sport Nutrition and Exercise Metabolism},

pages = {1–4},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{holwerda2024,

title = {Mitochondrial Bioenergetics Are Not Associated with Myofibrillar Protein Synthesis Rates},

author = {Andrew M. Holwerda and Marlou L. Dirks and Pierre-Andre Barbeau and Joy Goessens and Annemie Gijsen and Luc J. C. Loon and Graham P. Holloway},

doi = {10.1002/jcsm.13532},

issn = {2190-5991},

year  = {2024},

date = {2024-07-01},

journal = {Journal of cachexia, sarcopenia and muscle},

abstract = {Background Mitochondria represent key organelles influencing cellular homeostasis and have been implicated in the signalling events regulating protein synthesis. Methods We examined whether mitochondrial bioenergetics (oxidative phosphorylation and reactive oxygen species (H2O2) emission, ROS) measured in vitro in permeabilized muscle fibres represent regulatory factors for integrated daily muscle protein synthesis rates and skeletal muscle mass changes across the spectrum of physical activity, including free-living and bed-rest conditions: n = 19 healthy, young men (26 +/- 4 years, 23.4 +/- 3.3 kg/m(2)) and following 12 weeks of resistance-type exercise training: n = 10 healthy older men (70 +/- 3 years, 25.2 +/- 2.1 kg/m(2)). Additionally, we evaluated the direct relationship between attenuated mitochondrial ROS emission and integrated daily myofibrillar and sarcoplasmic protein synthesis rates in genetically modified mice (mitochondrial-targeted catalase, MCAT). Results Neither oxidative phosphorylation nor H2O2 emission were associated with muscle protein synthesis rates in healthy young men under free-living conditions or following 1 week of bed rest (both P $>$ 0.05). Greater increases in GSSG concentration were associated with greater skeletal muscle mass loss following bed rest (r = -0.49, P $<$ 0.05). In older men, only submaximal mitochondrial oxidative phosphorylation (corrected for mitochondrial content) was positively associated with myofibrillar protein synthesis rates during exercise training (r = 0.72, P $<$ 0.05). However, changes in oxidative phosphorylation and H2O2 emission were not associated with changes in skeletal muscle mass following training (both P $>$ 0.05). Additionally, MCAT mice displayed no differences in myofibrillar (2.62 +/- 0.22 vs. 2.75 +/- 0.15%/day) and sarcoplasmic (3.68 +/- 0.35 vs. 3.54 +/- 0.35%/day) protein synthesis rates when compared with wild-type mice (both P $>$ 0.05). Conclusions Mitochondrial oxidative phosphorylation and reactive oxygen emission do not seem to represent key factors regulating muscle protein synthesis or muscle mass regulation across the spectrum of physical activity.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{hilkens2024a,

title = {A Single Bout of Jumping Exercise Does Not Modulate Serum Markers of Bone Formation or Bone Resorption throughout a 24 h Period},

author = {Luuk Hilkens and Judith Bons and Jean Nyakayiru and Luc J C Loon and Jan-Willem Dijk},

doi = {10.1016/j.bone.2024.117216},

issn = {8756-3282},

year  = {2024},

date = {2024-07-01},

journal = {Bone},

number = {117216},

abstract = {INTRODUCTION: This randomized, cross-over trial assessed the effect of a single bout of high-impact exercise on serum markers of bone formation and bone resorption over a 24~h period. METHODS: Twenty healthy males and females performed a single bout of brief jumping exercise (EXC) or no exercise (CON), 55~min following consumption of a standard breakfast. Blood markers of bone formation (P1NP) and bone resorption (CTXI) were assessed before (t~=~0~h) and over a 5~h period after breakfast, and following 24~h of post-exercise recovery (t~=~24~h). RESULTS: Serum CTX-I concentrations decreased during the 5~h postprandial period (time-effect, P~$<~$0.001) with no differences between conditions (time x condition, P~=~0.14). After a~textasciitilde~16~% decline during the first 30~min following breakfast, serum P1NP concentrations gradually returned to baseline values during the 5~h postprandial period, with no differences in the overall response between conditions (time-effect, P~$<~$0.001; time x condition, P~=~0.25). Fasted serum CTX-I concentrations decreased from 0.33~±~0.15 and 0.35~±~0.15~ng/mL at baseline, to 0.31~±~0.13 and 0.31~±~0.16~ng/mL at t~=~24~h in CON and EXC, respectively, with no differences between conditions (time-effect, P~$<~$0.01; time x condition, P~=~0.70). Fasted serum P1NP concentrations did not change from baseline to t~=~24~h in both CON (baseline: 76~±~27~ng/mL, t~=~24~h: 79~±~26~ng/mL) and EXC (baseline: 80~±~24~ng/mL, t~=~24~h: 77~±~29~ng/mL; time-effect, P~=~0.89), with no differences between conditions (time x condition, P~=~0.22). CONCLUSION: High-impact exercise does not modulate the concentrations of the serum marker of bone formation P1NP and the serum marker of bone resorption CTX-I throughout a 24~h recovery period in healthy adults.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{aussieker2024,

title = {Coingestion of Collagen With Whey Protein Prevents Postexercise Decline in Plasma Glycine Availability in Recreationally Active Men},

author = {Thorben Aussieker and Tom A H Janssen and Wesley J H Hermans and Andrew M Holwerda and Joan M Senden and Janneau M X Kranenburg and Joy P B Goessens and Tim Snijders and Luc J C Loon},

doi = {10.1123/ijsnem.2023-0264},

issn = {1526-484X},

year  = {2024},

date = {2024-07-01},

journal = {International Journal of Sport Nutrition and Exercise Metabolism},

volume = {34},

number = {4},

pages = {189–198},

abstract = {Whey protein ingestion during recovery from exercise increases myofibrillar but not muscle connective protein synthesis rates. It has been speculated that whey protein does not provide sufficient glycine to maximize postexercise muscle connective protein synthesis rates. In the present study, we assessed the impact of coingesting different amounts of collagen with whey protein as a nutritional strategy to increase plasma glycine availability during recovery from exercise. In a randomized, double-blind, crossover design, 14 recreationally active men (age: 26 ± 5 years; body mass index: 23.8 ± 2.1 kg m-2) ingested in total 30 g protein, provided as whey protein with 0 g (WHEY), 5 g (WC05); 10 g (WC10), and 15 g (WC15) of collagen protein immediately after a single bout of resistance exercise. Blood samples were collected frequently over 6 hr of postexercise recovery to assess postprandial plasma amino acid kinetics and availability. Protein ingestion strongly increased plasma amino acid concentrations (p $<$ .001) with no differences in plasma total amino acid availability between treatments (p $>$ .05). The postprandial rise in plasma leucine and essential amino acid availability was greater in WHEY compared with the WC10 and WC15 treatments (p $<$ .05). Plasma glycine and nonessential amino acid concentrations declined following whey protein ingestion but increased following collagen coingestion (p $<$ .05). Postprandial plasma glycine availability averaged -8.9 ± 5.8, 9.2 ± 3.7, 23.1 ± 6.5, and 39.8 ± 11.0 mmol 360 min/L in WHEY, WC05, WC10, and WC15, respectively (incremental area under curve values, p $<$ .05). Coingestion of a small amount of collagen (5 g) with whey protein (25 g) is sufficient to prevent the decline in plasma glycine availability during recovery from lower body resistancetype exercise in recreationally active men.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{weijer2024a,

title = {Do Paralympic Athletes Suffer from Brittle Bones? Prevalence and Risk Factors of Low Bone Mineral Density in Paralympic Athletes},

author = {Vera C. R. Weijer and Jan Willem Dijk and Lotte Dam and Linn Risvang and Judith Bons and Truls Raastad and Luc J. C. Loon and Kristin L. Jonvik},

doi = {10.1016/j.bonr.2024.101767},

issn = {2352-1872},

year  = {2024},

date = {2024-06-01},

journal = {Bone Reports},

volume = {21},

number = {101767},

abstract = {Background: Bone health may be a concern in Paralympic athletes, given the presence of multiple risk factors predisposing these athletes to low bone mineral density (BMD). Objective: We aimed to assess the prevalence of low BMD among Paralympic athletes participating in various sport disciplines, and to identify potential risk factors for low BMD. Methods: Seventy Paralympic athletes, of whom 51 % were wheelchair-dependent, were included in this cross-sectional study. BMD of the whole-body, lumbar spine, total hip, and femoral neck were assessed by dual-energy x-ray absorptiometry. Comparisons between groups were conducted by one-way ANOVA, and regression analyses were conducted to identify potential risk factors for low BMD. Results: The prevalence of low BMD (Z-score $<$ -1.0) was highest at femoral neck (34 %), followed by total hip (31 %), whole-body (21 %), and lumbar spine (18 %). Wheelchair-dependent athletes had significantly lower BMD Z-scores compared to the non-wheelchair-dependent athletes at whole-body level (-0.5 ± 1.4 vs 0.2 ± 1.3; P = 0.04), total hip (-1.1 ± 1.2 vs 0.0 ± 1.1; P $<$ 0.01), and femoral neck (-1.0 ± 1.3 vs -0.1 ± 1.2; P $<$ 0.01). At the lumbar spine, low BMD was completely absent in wheelchair basketball and tennis players. Regression analyses identified body mass, wheelchair dependence, and type of sport, as the main risk factors for low BMD. Conclusions: In this cohort of Paralympic athletes, low BMD is mainly present at the hip, and to a lesser extent at the whole-body and lumbar spine. The most prominent risk factors for low BMD in Paralympic athletes are related to mechanical loading patterns, including wheelchair use, the type of sport, and body mass.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{weijzen2024a,

title = {Access to a Pre-Sleep Protein Snack Increases Daily Energy and Protein Intake in Surgical Hospitalized Patients},

author = {Michelle E. G. Weijzen and Maxime Kohlen and Alejandra Monsegue and Dion C. J. Houtvast and Jean Nyakayiru and Sandra Beijer and Phil Geerlings and Lex B. Verdijk and Luc J. C. Loon},

doi = {10.1016/j.clnu.2024.03.016},

issn = {0261-5614},

year  = {2024},

date = {2024-05-01},

journal = {Clinical Nutrition},

volume = {43},

number = {5},

pages = {1073–1078},

abstract = {Background & aim: In hospitalized patients, daily protein intake remains far below WHO requirements for healthy adults (0.8 g$cdot$kg-1$cdot$d-1) as well as ESPEN guidelines for patients (1.2–1.5 g$cdot$kg-1$cdot$d-1). Providing access to a pre-sleep protein dense snack between dinner and going to bed may serve as a great opportunity to increase daily energy and protein intake in hospitalized patients. However, it remains to be assessed whether protein provision prior to sleep effectively increases protein intake, or may reduce food intake throughout the remainder of the day(s). The present study evaluated the impact of giving access to a pre-sleep snack on daily energy and protein intake in patients throughout their hospitalization. Methods: Patients admitted to the surgical wards of the Maastricht University Medical Centre+ were randomly allocated to usual care (n = 51) or given access to a pre-sleep snack (n = 50). The pre-sleep snack consisted of 103 g cheese cubes (30 g protein) provided between 7:30 and 9:30 PM, prior to sleep. All food provided and all food consumed was weighed and recorded throughout (2–7 days) hospitalization. Daily energy and protein intake and distribution were calculated. Data were analyzed by independent T-Tests with P $<$ 0.05 considered as statistically significant. Results: Daily energy intake was higher in the pre-sleep group (1353 ± 424 kcal d-1) when compared to the usual care group (1190 ± 402 kcal$cdot$d-1; P = 0.049). Providing patients access to a pre-sleep snack resulted in a 17% (11 ± 9 g) higher daily protein intake (0.81 ± 0.29 g$cdot$kg-1$cdot$d-1) when compared to the usual care group (0.69 ± 0.28 g$cdot$kg-1$cdot$d-1; P = 0.045). Protein intake at breakfast, lunch, and dinner did not differ between the pre-sleep and usual care groups (all P $>$ 0.05). Conclusion: Providing access to a pre-sleep protein snack, in the form of protein dense food items such as cheese, represents an effective dietary strategy to increase daily energy and protein intake in hospitalized patients. Patients consuming pre-sleep protein snacks do not compensate by lowering energy or protein intake throughout the remainder of the days. Pre-sleep protein dense food provision should be implemented in hospital food logistics to improve the nutritional intake of patients. Trial register no: NL8507 (https://trialsearch.who.int/)},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{trommelen2024,

title = {Quantification and Interpretation of Postprandial Whole-Body Protein Metabolism Using Stable Isotope Methodology: A Narrative Review},

author = {Jorn Trommelen and Luc J. C. Loon},

doi = {10.3389/fnut.2024.1391750},

issn = {2296-861X},

year  = {2024},

date = {2024-05-01},

journal = {Frontiers in nutrition},

volume = {11},

number = {1391750},

abstract = {Stable isotopes are routinely applied to determine the impact of factors such as aging, disease, exercise, and feeding on whole-body protein metabolism. The most common approaches to quantify whole-body protein synthesis, breakdown, and oxidation rates and net protein balance are based on the quantification of plasma amino acid kinetics. In the postabsorptive state, plasma amino acid kinetics can easily be assessed using a constant infusion of one or more stable isotope labeled amino acid tracers. In the postprandial state, there is an exogenous, dietary protein-derived amino acid flux that needs to be accounted for. To accurately quantify both endogenous as well as exogenous (protein-derived) amino acid release in the circulation, the continuous tracer infusion method should be accompanied by the ingestion of intrinsically labeled protein. However, the production of labeled protein is too expensive and labor intensive for use in more routine research studies. Alternative approaches have either assumed that 100% of exogenous amino acids are released in the circulation or applied an estimated percentage based on protein digestibility. However, such estimations can introduce large artifacts in the assessment of whole-body protein metabolism. The preferred estimation approach is based on the extrapolation of intrinsically labeled protein-derived plasma bioavailability data obtained in a similar experimental design setting. Here, we provide reference data on exogenous plasma amino acid release that can be applied to allow a more accurate routine assessment of postprandial protein metabolism. More work in this area is needed to provide a more extensive reference data set.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{monsegue2024,

title = {Resistance Exercise Training to Improve Post-Operative Rehabilitation in Knee Arthroplasty Patients: A Narrative Review},

author = {Alejandra P. Monsegue and Pieter Emans and Luc J. C. Loon and Lex B. Verdijk},

doi = {10.1002/ejsc.12114},

issn = {1746-1391},

year  = {2024},

date = {2024-05-01},

journal = {European Journal of Sport Science},

abstract = {Knee osteoarthritis is associated with deficits in muscle strength, muscle mass, and physical functioning. These muscle-related deficits are acutely exacerbated following total knee arthroplasty (TKA) and persist long after surgery, despite the application of standardized rehabilitation programs that include physical/functional training. Resistance exercise training (RET) has been shown to be a highly effective strategy to improve muscle-related outcomes in healthy as well as clinical populations. However, the use of RET in traditional rehabilitation programs after TKA is limited. In this narrative review, we provide an updated view on whether adding RET to the standard rehabilitation (SR) in the recovery period (up to 1 year) after TKA leads to greater improvements in muscle-related outcomes when compared to SR alone. Overall, research findings clearly indicate that both muscle strength and muscle mass can be improved to a greater extent with RET-based rehabilitation compared to SR. Additionally, measures of physical functioning that rely on quadriceps strength and balance (e.g., stair climbing, chair standing, etc.) also appear to benefit more from a RET-based program compared to SR, especially in patients with low levels of physical functioning. Importantly though, for RET to be optimally effective, it should be performed at 70%-80% of the one-repetition maximum, with 3-4 sets per exercise, with a minimum of 3 times per week for 8 weeks. Based upon this narrative review, we recommend that such high-intensity progressive RET should be incorporated into standard programs during rehabilitation after TKA.Schematic summary of this narrative review. Osteoarthritis is associated with a decline in muscle strength, mass, and function (1). After total knee replacement a further decline in muscle strength, mass, and function is observed (2). Although standard rehabilitation results in a partial or (sometimes) full recovery in these outcomes (3a), rehabilitation involving high-intensity resistance exercise training leads to greater improvements in muscle strength, muscle mass, and physical functioning compared to standard rehabilitation (3b). imageFollowing standard rehabilitation (SR) protocols, patients recovering from total knee replacement still have deficits in muscle strength, muscle mass, and physical functioning compared to their healthy counterparts. Rehabilitation involving high-intensity resistance exercise training (RET) following total knee replacement leads to greater improvements in muscle strength, muscle mass, and physical functioning compared to SR. We recommend incorporating high intensity RET in the SR following total knee arthroplasty.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{hendriks2024,

title = {Hemodialysis Does Not Lower Circulating Testosterone Concentrations},

author = {Floris K Hendriks and Jos Wiersma and Frank M Sande and Sarah E Alexander and Jeroen P Kooman and Judith A P Bons and Luc J C Loon},

doi = {10.1007/s40620-023-01810-w},

issn = {1121-8428},

year  = {2024},

date = {2024-05-01},

journal = {Journal of Nephrology},

volume = {37},

number = {4},

pages = {1125–1127},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{bland2024,

title = {``It Gave Me a Sense of Achievement and a Sense of Purpose''—a Qualitative Study of Patient Experiences of a Virtually Supervised Exercise Program for Adults with Advanced Cancer and Cachexia},

author = {Kelcey A. Bland and Madeleine France-Ratcliffe and Meinir Krishnasamy and Amruta Nandi and Evelyn B. Parr and Peter Martin and Prue Cormie and Luc J. C. Loon and Eva M. Zopf},

doi = {10.1007/s00520-024-08526-y},

issn = {0941-4355},

year  = {2024},

date = {2024-05-01},

journal = {Supportive Care in Cancer},

volume = {32},

number = {5},

abstract = {Abstract: People with advanced cancer and cachexia experience significant body weight loss, adversely impacting physical function and quality of life (QOL). Effective, evidence-based treatments for cancer cachexia are lacking, leaving patients with unmet needs. Exercise holds promise to improve patient QOL. However, information on patients' experiences of exercise, including their ability to cope with structured exercise, is limited. Purpose: To explore patient experiences completing a structured, supervised exercise program for people with cachexia due to advanced cancer. Methods: Semi-structured interviews were conducted with participants enrolled in a phase II feasibility, randomized controlled trial to explore their experiences of an 8-week virtually supervised exercise program delivered via videoconference technology. Interviews were analysed using reflexive thematic analysis. Results: Seventeen participants completed interviews (female n = 9, 53%). Main interview themes included the following: (1) Deciding to exercise involves balancing concerns and expectations, (2) the exercise program is a positive experience, and (3) moving forward after the exercise program. While some participants initially held doubts about their physical capabilities and exercise safety, most wanted to exercise to enhance their wellbeing. Participants described the exercise program as a positive experience, offering diverse benefits. Some would have preferred in-person exercise, but all agreed the virtual format increased convenience. Participants emphasized the need to recommend the program to others in similar circumstances. They underscored the necessity and desire for ongoing support to sustain their new exercise habits. Conclusion: Based on patient experiences, virtually supervised exercise programming appears to be feasible and meaningful to people with advanced cancer and cachexia.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pinckaers2024a,

title = {Post-Prandial Muscle Protein Synthesis Rates Following the Ingestion of Pea-Derived Protein Do Not Differ from Ingesting an Equivalent Amount of Milk-Derived Protein in Healthy, Young Males},

author = {Philippe J M Pinckaers and Joey S J Smeets and Imre W K Kouw and Joy P B Goessens and Annemarie P B Gijsen and Lisette C P G M Groot and Lex B Verdijk and Luc J C Loon and Tim Snijders},

doi = {10.1007/s00394-023-03295-6},

issn = {1436-6215},

year  = {2024},

date = {2024-04-01},

journal = {European journal of nutrition},

volume = {63},

number = {3},

pages = {893–904},

abstract = {PURPOSE: Plant-derived proteins have received considerable attention as an alternative to animal-derived proteins. However, plant-derived proteins are considered to have less anabolic properties when compared with animal-derived proteins. The lower muscle protein synthesis rates following ingestion of plant- compared with animal-derived protein have been attributed to the lower essential amino acid content of plant-derived proteins and/or their specific amino acid deficiencies. This study aimed to compare post-prandial muscle protein synthesis rates following the ingestion of 30 g pea-derived protein with 30 g milk-derived protein in healthy, young males.nnMETHODS: In a randomized, double-blind, parallel-group design, 24 young males (24 ± 3 y) received a primed continuous L-[ring-C]-phenylalanine infusion after which they ingested 30 g pea (PEA) or 30 g milk-derived protein (MILK). Blood and muscle biopsies were collected frequently for 5 h to assess post-prandial plasma amino acid profiles and subsequent post-prandial muscle protein synthesis rates.nnRESULTS: MILK increased plasma essential amino acid concentrations more than PEA over the 5 h post-prandial period (incremental area under curve 151 ± 31 vs 102 ± 15 mmol$bullet$300 min$bullet$L, respectively; P ¡ 0.001). Ingestion of both MILK and PEA showed a robust muscle protein synthetic response with no significant differences between treatments (0.053 ± 0.013 and 0.053 ± 0.017%$bullet$h, respectively; P = 0.96).nnCONCLUSION: Post-prandial muscle protein synthesis rates following the ingestion of 30 g pea-derived protein do not differ from the response following ingestion of an equivalent amount of milk-derived protein. International Clinical Trials Registry Platform (NTR6548; 27-06-2017).},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{houben2024a,

title = {A Low or High Physical Activity Level Does Not Modulate Prostate Tumor Tissue Protein Synthesis Rates},

author = {Lisanne H P Houben and Tom Tuytten and Andrew M Holwerda and Erika Wisanto and Joan Senden and Will K W H Wodzig and Steven W M Olde Damink and Milou Beelen and Sandra Beijer and Koenraad VAN Renterghem and Luc J C VAN Loon},

doi = {10.1249/MSS.0000000000003349},

issn = {1530-0315},

year  = {2024},

date = {2024-04-01},

journal = {Medicine and science in sports and exercise},

volume = {56},

number = {4},

pages = {635–643},

abstract = {INTRODUCTION: Physical activity level has been identified as an important factor in the development and progression of various types of cancer. In this study, we determined the impact of a low versus high physical activity level on skeletal muscle, healthy prostate, and prostate tumor protein synthesis rates in vivo in prostate cancer patients.nnMETHODS: Thirty prostate cancer patients (age, 66 ± 5 yr; body mass index, 27.4 ± 2.9 kg$cdot$m -2 ) were randomized to a low (¡4000 steps per day},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{holwerda2024a,

title = {One Week of Single-Leg Immobilization Lowers Muscle Connective Protein Synthesis Rates in Healthy, Young Adults},

author = {Andrew M Holwerda and Michelle E G Weijzen and Antoine Zorenc and Joan Senden and Guus H J Jetten and Lisanne H P Houben and Lex B Verdijk and Luc J C VAN Loon},

doi = {10.1249/MSS.0000000000003342},

issn = {1530-0315},

year  = {2024},

date = {2024-04-01},

urldate = {2024-04-01},

journal = {Medicine and science in sports and exercise},

volume = {56},

number = {4},

pages = {612–622},

abstract = {PURPOSE: Short periods of limb immobilization lower myofibrillar protein synthesis rates. Within skeletal muscle, the extracellular matrix of connective proteins is recognized as an important factor determining the capacity to transmit contractile force. Little is known regarding the impact of immobilization and subsequent recovery on muscle connective protein synthesis rates. This study examined the impact of 1 wk of leg immobilization and 2 wk of subsequent ambulant recovery on daily muscle connective protein synthesis rates. METHODS: Thirty healthy, young (24 ± 5 yr) men were subjected to 7 d of one-legged knee immobilization followed by 14 d of ambulant recovery. Deuterium oxide ingestion was applied over the entire period, and muscle biopsy samples were collected before immobilization, after immobilization, and after recovery to measure muscle connective protein synthesis rates and mRNA expression of key extracellular matrix proteins (collagen I, collagen III), glycoproteins (fibronectin, tenascin-C), and proteoglycans (fibromodulin, and decorin). A two-way repeated-measures (time-leg) ANOVA was used to compare changes in muscle connective protein synthesis rates during immobilization and recovery. RESULTS: During immobilization, muscle connective protein synthesis rates were lower in the immobilized (1.07 ± 0.30%$cdot$d -1 ) compared with the nonimmobilized (1.48 ± 0.44%$cdot$d -1 ; P < 0.01) leg. When compared with the immobilization period, connective protein synthesis rates in the immobilized leg increased during subsequent recovery (1.48 ± 0.64%$cdot$d -1 ; P < 0.01). After recovery, skeletal muscle collagen I, collagen III, fibronectin, fibromodulin, and decorin mRNA expression increased when compared with the postimmobilization time point (all P < 0.001). CONCLUSIONS: One week of leg immobilization lowers muscle connective protein synthesis rates. Muscle connective protein synthesis rates increase during subsequent ambulant recovery, which is accompanied by increased mRNA expression of key extracellular matrix proteins.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{houben2024b,

title = {Resistance Exercise Training, a Simple Intervention to Preserve Muscle Mass and Strength in Prostate Cancer Patients on Androgen Deprivation Therapy},

author = {Lisanne H P Houben and Milou Beelen and Luc J C Loon and Sandra Beijer},

doi = {10.1123/ijsnem.2023-0075},

issn = {1543-2742},

year  = {2024},

date = {2024-03-01},

journal = {International journal of sport nutrition and exercise metabolism},

volume = {34},

number = {2},

pages = {122–134},

abstract = {Androgen deprivation therapy (ADT) forms the cornerstone in the treatment of advanced prostate cancer. However, by suppressing testosterone ADT results in a decrease of skeletal muscle mass. In this narrative review, we explore the magnitude and mechanisms of ADT-induced muscle mass loss and the consequences for muscle strength and physical performance. Subsequently, we elucidate the effectiveness of supervised resistance exercise training as a means to mitigate these adverse effects. Literature shows that resistance exercise training can effectively counteract ADT-induced loss of appendicular lean body mass and decline in muscle strength, while the effect on physical performances is inconclusive. As resistance exercise training is feasible and can be safely implemented during ADT (with special attention for patients with bone metastases), it should be incorporated in standard clinical care for prostate cancer patients (starting) with ADT.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{fuchs2024,

title = {Becoming a World Champion Powerlifter at 71 Years of Age: It Is Never Too Late to Start Exercising},

author = {Cas J Fuchs and Jorn Trommelen and Michelle E G Weijzen and Joey S J Smeets and Janneau Kranenburg and Lex B Verdijk and Luc J C Loon},

doi = {10.1123/ijsnem.2023-0230},

issn = {1526-484X},

year  = {2024},

date = {2024-03-01},

journal = {International Journal of Sport Nutrition and Exercise Metabolism},

pages = {1–9},

abstract = {This case study assessed body composition, muscle strength, cardiorespiratory fitness, and metabolic health of the present female world champion powerlifter in the 70+ age category who started resistance exercise training at 63~years of age with no prior experience with structured exercise training. Measures of body composition (magnetic resonance imaging, computed tomography, and dual-energy X-ray absorptiometry scanning, leg volume); strength (one-repetition maximum leg press and extension, maximum voluntary contraction, and handgrip strength); physical function (short physical performance battery); cardiorespiratory fitness (peak oxygen consumption); and metabolic health (oral glucose tolerance test) were assessed. In addition, a muscle biopsy was collected to assess muscle fiber type distribution and cross-sectional area (CSA). Where possible, data were compared with previously (un)published sex- and age-matched data using z scores. Skeletal muscle mass index was calculated by dividing limb muscle mass by height squared. Data from the control groups are expressed as mean ± 95% confidence interval. Our participant (age: 71~years; body mass: 64.5~kg; body mass index: 27.6~kg/m2) reported a good bone mineral density of 1.09~g/cm2 (T score between -1 and +1) and very low values of abdominal and organ body fat (i.e.,~between 20% and 70% lower compared with a reference group of postmenopausal women). In addition, she showed a 33% greater skeletal muscle mass index when compared with healthy, older female control subjects (7.9 vs. 5.9 [5.7-6.2] kg/m2; n = 61) as well as 37% greater muscle quadriceps CSA (63.8 vs. 46.6 [44.5-48.7] cm2; n = 48) and 46% greater Type II muscle fiber CSA (4,536 vs. 3,097 [2,707-3,488] µm2; n = 19). Absolute leg press muscle strength was 36% greater (190 vs. 140 [132-147] kg; n = 30) and handgrip strength was 33% greater (33 vs. 25 [23-26] kg; n = 48) when compared with healthy, age-matched controls. In conclusion, even for resistance exercise naïve individuals, starting exercise at an advanced age can lead to improvements in body composition and muscle strength allowing older adults to reduce the risk for developing metabolic syndrome, live independently, and even compete at a world class level.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{vangassel2024,

title = {Administration of Free Amino Acids Improves Exogenous Amino Acid Availability When Compared with Intact Protein in Critically Ill Patients: A Randomized Controlled Study},

author = {Rob Jj Gassel and Michelle Eg Weijzen and Imre Wk Kouw and Joan Mg Senden and Will Khw Wodzig and Steven Wm Olde Damink and Marcel Cg Poll and Luc Jc Loon},

doi = {10.1016/j.tjnut.2023.12.015},

issn = {0022-3166},

year  = {2024},

date = {2024-02-01},

journal = {Journal of Nutrition},

volume = {154},

number = {2},

pages = {554–564},

abstract = {Background: Protein digestion and amino acid absorption appear compromised in critical illness. The provision of enteral feeds with free amino acids rather than intact protein may improve postprandial amino acid availability. Objective: Our objective was to quantify the uptake of diet-derived phenylalanine after the enteral administration of intact protein compared with an equivalent amount of free amino acids in critically ill patients. Methods: Sixteen patients who were mechanically ventilated in intensive care unit (ICU) at risk of malabsorption received a primed continuous infusion of L-[ring- 2H 5]-phenylalanine and L-[ring-3,5- 2H 2]-tyrosine after an overnight fast. Patients were randomly allocated to receive 20 g intrinsically L-[1- 13C]-phenylalanine-labeled milk protein or an equivalent amount of amino acids labeled with free L-[1- 13C]-phenylalanine via a nasogastric tube over a 2-h period. Protein digestion and amino acid absorption kinetics and whole-body protein net balance were assessed throughout a 6-h period. Results: After enteral nutrient infusion, both plasma phenylalanine and leucine concentrations increased (P-time $<$ 0.001), with a more rapid and greater rise after free amino acid compared with intact protein administration (P-time × treatment = 0.003). Diet-derived phenylalanine released into the circulation was 25% greater after free amino acids compared with intact protein administration [68.7% (confidence interval CI: 62.3, 75.1%) compared with 43.8% (CI: 32.4, 55.2%), respectively; P $<$ 0.001]. Whole-body protein net balance became positive after nutrient administration (P-time $<$ 0.001) and tended to be more positive after free amino acid in provision (P-time × treatment = 0.07). Conclusions: The administration of free amino acids as opposed to intact protein further increases postprandial plasma amino acid availability in critically ill patients, allowing more diet-derived phenylalanine to become available to peripheral tissues. This trial was registered at clinicaltrials.gov as NCT04791774.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pinckaers2024,

title = {The Muscle Protein Synthetic Response Following Corn Protein Ingestion Does Not Differ from Milk Protein in Healthy, Young Adults},

author = {Philippe J M Pinckaers and Michelle E G Weijzen and Lisanne H P Houben and Antoine H Zorenc and Imre W K Kouw and Lisette C P G M Groot and Lex B Verdijk and Tim Snijders and Luc J C Loon},

doi = {10.1007/s00726-023-03377-z},

issn = {1438-2199},

year  = {2024},

date = {2024-02-01},

journal = {Amino Acids},

volume = {56},

number = {1},

pages = {8},

abstract = {Plant-derived proteins are generally believed to possess lesser anabolic properties when compared with animal-derived proteins. This is, at least partly, attributed to the lower leucine content of most plant-derived proteins. Corn protein has a leucine content that is highest among most plant-derived proteins and it even exceeds the levels observed in animal-derived proteins such as whey protein. Therefore, this study aimed to compare muscle protein synthesis rates following the ingestion of 30 g corn protein and a 30 g blend of corn plus milk protein with 30 g milk protein. In a randomized, double blind, parallel-group design, 36 healthy young males (26 ± 4 y) received primed continuous L-[ring-C]-phenylalanine infusions and ingested 30 g corn protein (CORN), 30 g milk protein (MILK), or a 30 g proteinblend with 15 g corn plus 15 g milk protein (CORN + MILK). Blood and muscle biopsies were collected for 5 h following protein ingestion to assess post-prandial plasma amino acid profiles and myofibrillar protein synthesis rates. The results show that Ingestion of protein increased myofibrillar protein synthesis rates from basal post-absorptive values in all treatments(P ¡ 0.001). Post-prandial myofibrillar protein synthesis rates did not differ between CORN vs MILK (0.053 ± 0.013 vs 0.053 ± 0.013%$bullet$h, respectively; t-test P = 0.90), or between CORN + MILK vs MILK (0.052 ± 0.024 vs 0.053 ± 0.013%$bullet$h, respectively; t-test P = 0.92). Ingestion of 30 g corn protein, 30 g milk protein, or a blend of 15 g corn plus 15 g milk protein robustly increases muscle protein synthesis rates in young males. The muscle protein synthetic response to the ingestion of 30 g corn-derived protein does not differ from the ingestion of an equivalent amount of milk protein in healthy, young males. Clinical Trial Registry number. NTR6548 (registration date: 27-06-2017) https://www.trialregister.nl/ .},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{hilkens2024,

title = {Graded Replacement of Carbohydrate-Rich Breakfast Products with Dairy Products: Effects on Postprandial Aminoacidemia, Glycemic Control, Bone Metabolism, and Satiety},

author = {Luuk Hilkens and Floor Praster and Jan Overdam and Jean Nyakayiru and Cécile M Singh-Povel and Judith Bons and Luc Jc Loon and Jan-Willem Dijk},

doi = {10.1016/j.tjnut.2023.12.012},

issn = {0022-3166},

year  = {2024},

date = {2024-02-01},

journal = {Journal of Nutrition},

volume = {154},

number = {2},

pages = {479–490},

abstract = {Background: Postprandial metabolic responses following dairy consumption have mostly been studied using stand-alone dairy products or milk-derived nutrients. Objective: Assessing the impact of ingesting dairy products as part of a common breakfast on postprandial aminoacidemia, glycemic control, markers of bone metabolism, and satiety. Methods: In this randomized, crossover study, 20 healthy young males and females consumed on 3 separate occasions an iso-energetic breakfast containing no dairy (NO-D), 1 dairy (ONE-D), or 2 dairy (TWO-D) products. Postprandial concentrations of amino acids, glucose, insulin, glucagon-like peptide-1 (GLP-1), calcium, parathyroid hormone (PTH), and markers of bone formation (P1NP) and resorption (CTX-I) were measured before and up to 300 min after initiating the breakfast, along with VAS-scales to assess satiety. Results: Plasma essential and branched-chained amino acids availability (expressed as total area under the curve (tAUC)) increased in a dose-dependent manner (P$<$0.05 for all comparisons). Plasma glucose tAUCs were lower in ONE-D and TWO-D compared with NO-D (P$<$0.05 for both comparisons). Plasma GLP-1 tAUC increased in a dose-dependent manner (P$<$0.05 for all comparisons), whereas no differences were observed in plasma insulin tAUC between conditions (P$>$0.05 for all comparisons). Serum calcium tAUCs were higher in ONE-D and TWO-D compared with NO-D (P$<$0.05 for both comparisons), along with lower PTH tAUCs in ONE-D and TWO-D compared with NO-D (P=0.001 for both comparisons). In accordance, serum CTX-I concentrations were lower in the late postprandial period in ONE-D and TWO-D compared with NO-D (P$<$0.01 for both comparisons). No differences were observed in P1NP tAUCs between conditions (P$>$0.05). The tAUC for satiety was higher in TWO-D compared with NO-D and ONE-D (P$<$0.05 for both comparisons). Conclusions: Iso-energetic replacement of a carbohydrate-rich breakfast component with one serving of dairy improves postprandial amino acid availability, glycemic control, and bone metabolism. Adding a second serving of dairy in lieu of carbohydrates augments postprandial amino acid and GLP-1 concentrations while further promoting satiety. This study was registered at https://doi.org/10.1186/ISRCTN13531586 with Clinical Trial Registry number ISRCTN13531586.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{fuchs2024a,

title = {Daily Blood Flow Restriction Does Not Preserve Muscle Mass and Strength during 2 Weeks of Bed Rest},

author = {Cas J Fuchs and Wesley J H Hermans and Jean Nyakayiru and Michelle E G Weijzen and Joey S J Smeets and Thorben Aussieker and Joan M Senden and Will K H W Wodzig and Tim Snijders and Lex B Verdijk and Luc J C Loon},

doi = {10.1113/JP286065},

issn = {1469-7793},

year  = {2024},

date = {2024-02-01},

journal = {The Journal of physiology},

abstract = {We measured the impact of blood flow restriction on muscle protein synthesis rates, muscle mass and strength during 2 weeks of strict bed rest. Twelve healthy, male adults (age: 24 ± 3 years, body mass index: 23.7 ± 3.1 kg/m ) were subjected to 14 days of strict bed rest with unilateral blood flow restriction performed three times daily in three 5 min cycles (200 mmHg). Participants consumed deuterium oxide and we collected blood and saliva samples throughout 2 weeks of bed rest. Before and immediately after bed rest, lean body mass (dual-energy X-ray absorptiometry scan) and thigh muscle volume (magnetic resonance imaging scan) were assessed in both the blood flow restricted (BFR) and control (CON) leg. Muscle biopsies were collected and unilateral muscle strength (one-repetition maximum; 1RM) was assessed for both legs before and after the bed rest period. Bed rest resulted in 1.8 ± 1.0 kg lean body mass loss (P ¡ 0.001). Thigh muscle volume declined from 7.1 ± 1.1 to 6.7 ± 1.0 L in CON and from 7.0 ± 1.1 to 6.7 ± 1.0 L in BFR (P ¡ 0.001), with no differences between treatments (P = 0.497). In addition, 1RM leg extension strength decreased from 60.2 ± 10.6 to 54.8 ± 10.9 kg in CON and from 59.2 ± 12.1 to 52.9 ± 12.0 kg in BFR (P = 0.014), with no differences between treatments (P = 0.594). Muscle protein synthesis rates during bed rest did not differ between the BFR and CON leg (1.11 ± 0.12 vs. 1.08 ± 0.13%/day, respectively; P = 0.302). Two weeks of bed rest substantially reduces skeletal muscle mass and strength. Blood flow restriction during bed rest does not modulate daily muscle protein synthesis rates and does not preserve muscle mass or strength. KEY POINTS: Bed rest, often necessary for recovery from illness or injury, leads to the loss of muscle mass and strength. It has been postulated that blood flow restriction may attenuate the loss of muscle mass and strength during bed rest. We investigated the effect of blood flow restriction on muscle protein synthesis rates, muscle mass and strength during 2 weeks of strict bed rest. Blood flow restriction applied during bed rest does not modulate daily muscle protein synthesis rates and does not preserve muscle mass or strength. Blood flow restriction is not effective in preventing muscle atrophy during a prolonged period of bed rest.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{weijer2024b,

title = {Energy Requirements of Paralympic Athletes: Insights from the Doubly Labeled Water Approach},

author = {Vera C R Weijer and Kristin L Jonvik and Lotte Dam and Linn Risvang and Guy Plasqui and Øyvind Sandbakk and Truis Raastad and Luc J C Loon and Jan-Willem Dijk},

doi = {10.1249/MSS.0000000000003379},

issn = {1530-0315},

year  = {2024},

date = {2024-01-01},

journal = {Medicine and science in sports and exercise},

abstract = {PURPOSE: Advanced insight in energy requirements of Paralympic athletes is imperative for optimizing their nutritional counseling. Given the lack of accurate data on total daily energy expenditure (TDEE) of Paralympic athletes, this study aimed to assess energy expenditure and nutritional intake of a large cohort of Paralympic athletes, across different sports and disabilities.nnMETHODS: In this cross-sectional study, 48 Dutch and Norwegian Paralympic athletes (19 male/29 female) with various disabilities, competing in Para cycling, wheelchair tennis, wheelchair basketball, Para Nordic skiing and alpine skiing participated. TDEE was assessed by the gold standard doubly labeled water method over a 14-day period, resting metabolic rate (RMR) by ventilated hood indirect calorimetry, energy intake (EI) by three unannounced 24 h-dietary recalls, body composition by dual energy x-ray absorptiometry and exercise training duration by a training log.nnRESULTS: Mean TDEE was 2908 ± 797 kcal/day, ranging from 2322 ± 340 kcal/day for wheelchair basketball players to 3607 ± 1001 kcal/day for Para cyclists. Regression analysis identified fat-free mass, exercise duration, and the presence of a spinal cord disorder as the primary predictors of TDEE, explaining up to 73% of the variance in TDEE. Athletes' EI (2363 ± 905 kcal/day) was below their TDEE, while their body mass remained constant, indicating underreporting. Carbohydrate intake (4.1 ± 1.9 g/kg body mass) was low, even when considering underreporting, while protein intake (1.8 ± 0.6 g/kg body mass) was relatively high.nnCONCLUSIONS: Paralympic athletes display moderate to high energy expenditure, varying across sports and individuals. Much of the variation in TDEE can be attributed to individual differences in fat free mass and exercise duration. This study establishes the benchmarks for energy requirements of Paralympic athletes, serving as the foundation for future dietary guidelines within this population.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{marzuca-nassr2024,

title = {Muscle Mass and Strength Gains Following Resistance Exercise Training in Older Adults 65-75 Years and Older Adults above 85 Years},

author = {Gabriel Nasri Marzuca-Nassr and Andrea Alegría-Molina and Yuri SanMartín-Calísto and Macarena Artigas-Arias and Nolberto Huard and Jorge Sapunar and Luis A Salazar and Lex B Verdijk and Luc J C Loon},

doi = {10.1123/ijsnem.2023-0087},

issn = {1543-2742},

year  = {2024},

date = {2024-01-01},

journal = {International journal of sport nutrition and exercise metabolism},

volume = {34},

number = {1},

pages = {11–19},

abstract = {Resistance exercise training (RET) can be applied effectively to increase muscle mass and function in older adults (65-75 years). However, it has been speculated that older adults above 85 years are less responsive to the benefits of RET. This study compares the impact of RET on muscle mass and function in healthy older adults 65-75 years versus older adults above 85 years. We subjected 17 healthy older adults 65-75 years (OLDER 65-75},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{kirmse2024,

title = {Collagen Peptide Supplementation during Training Does Not Further Increase Connective Tissue Protein Synthesis Rates},

author = {Marius Kirmse and Theo Maria Lottmann and Nicola Reiner Volk and Markus Marées and Andrew M. Holwerda and Luc J. C. Loon and Petra Platen},

doi = {10.1249/MSS.0000000000003519},

issn = {0195-9131},

year  = {2024},

date = {2024-01-01},

journal = {Medicine and Science in Sports and Exercise},

abstract = {Introduction: Protein supplementation increases post-exercise muscle protein synthesis rates and, as such, supports exercise-induced muscle conditioning. Collagen protein has been suggested as the preferred protein source to stimulate muscle connective protein synthesis rates during recovery from exercise. Here we assessed the effects of hydrolyzed collagen peptide supplementation on both myofibrillar as well as muscle connective protein synthesis rates during one week of strenuous resistance exercise training. Methods: In a randomized, double-blind, parallel design, 25 young men (24±3 y, 76.9±6.4 kg) were selected to perform one week of intense resistance-type exercise training. Subjects were randomly assigned into two groups receiving either 15 g hydrolyzed collagen peptides (COL) or a non-caloric placebo (PLA) twice daily during the intervention. Subjects were administered deuterated water (2H2O) daily, with blood and skeletal muscle tissue samples being collected prior to and after the intervention to determine daily myofibrillar and muscle connective protein synthesis rates. Results: Post-absorptive plasma glycine, proline, and hydroxyproline concentrations increased following collagen peptide supplementation (p$<$0.05) and showed higher levels when compared to the placebo group (p$<$0.05). Daily muscle connective protein synthesis rates during the intervention period exceeded myofibrillar protein synthesis rates (1.99±0.38 versus 1.34±0.23 %/d, respectively; p$<$0.001). Collagen peptide supplementation did not result in higher myofibrillar or muscle connective protein synthesis rates (1.34±0.19 and 1.97±0.47 %/d, respectively) when compared to the placebo group (1.34±0.27 and 2.00±0.27 %/d, respectively; p$>$0.05). Conclusions: Collagen peptide supplementation (2 x 15 g daily) does not increase myofibrillar or muscle connective protein synthesis rates during one week of intense resistance exercise training in young, recreational athletes.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{houben2024,

title = {Benefits of Resistance Training Are Not Preserved after Cessation of Supervised Training in Prostate Cancer Patients on Androgen Deprivation Therapy},

author = {Lisanne H. P. Houben and Maarten Overkamp and Joan M. G. Senden and Joep G. H. Roermund and Peter Vries and Kevin Laet and Saskia Meer and Luc J. C. Loon and Milou Beelen and Sandra Beijer},

doi = {10.1002/ejsc.12050},

issn = {1746-1391},

year  = {2024},

date = {2024-01-01},

journal = {European Journal of Sport Science},

volume = {24},

number = {1},

pages = {116–126},

abstract = {Resistance exercise training is effective to counteract the adverse effects of androgen deprivation therapy (ADT) on body composition, muscle mass and leg strength in prostate cancer patients (PCa). However, it is unknown whether these effects can be autonomously maintained after cessation of the supervised program. Sixty-eight PCa patients on ADT were included. The exercise intervention group (EX},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{brinkmans2024,

title = {Energy Expenditure and Dietary Intake in Professional Female Football Players in the Dutch Women's League: Implications for Nutritional Counselling},

author = {Naomi Brinkmans and Guy Plasqui and Luc Loon and Jan-Willem Dijk},

doi = {10.1080/02640414.2024.2329850},

issn = {0264-0414},

year  = {2024},

date = {2024-01-01},

journal = {Journal of Sports Sciences},

volume = {42},

number = {4},

pages = {313–322},

abstract = {In contrast to male football players, research on the nutritional requirements of female football players is limited. This study aimed to assess total daily energy expenditure (TDEE) in professional female football players, along with body composition, physical activity and dietary intake. This observational study included 15 professional football players playing in the highest Dutch Women's League. TDEE was assessed by doubly labelled water over 14 days, along with resting metabolic rate (RMR; ventilated hood), fat-free mass (FFM; dual-energy x-ray absorptiometry), and dietary intake (24-h recalls). Physical activity energy expenditure (PAEE) was derived from subtracting RMR and estimated diet-induced thermogenesis (10%) from TDEE. TDEE was 2882 ± 278 kcal/day (58 ± 5 kcal/kg FFM) and significantly (p $<$ 0.05) correlated with FFM (r = 0.62). PAEE was 1207 ± 213 kcal/d. Weighted energy intake was 2344 kcal [2023–2589]. Carbohydrate intakes were 3.2 ± 0.7, 4.4 ± 1.1 and 5.3 ± 1.9 g/kg body mass for rest, training and match days, respectively, while weighted mean protein intake was 1.9 ± 0.4 g/kg body mass. In conclusion, the energy requirements of professional female football players are moderate to high and can be explained by the substantial PAEE. To fuel these requirements, sports nutritionists should consider shifting the players' focus towards prioritizing adequate carbohydrate intakes, rather than emphasizing high protein consumption.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{betz2024,

title = {Type II Muscle Fiber Capillarization Is an Important Determinant of Post-Exercise Microvascular Perfusion in Older Adults},

author = {Milan W Betz and Floris K Hendriks and Alfons J H M Houben and Mathias D G Eynde and Lex B Verdijk and Luc J C Loon and Tim Snijders},

doi = {10.1159/000535831},

issn = {1423-0003},

year  = {2024},

date = {2024-01-01},

journal = {Gerontologia},

volume = {70},

number = {3},

pages = {290–301},

abstract = {INTRODUCTION: Microvascular perfusion is essential for post-exercise skeletal muscle recovery to ensure adequate delivery of nutrients and growth factors. This study assessed the relationship between various indices of muscle fiber capillarization and microvascular perfusion assessed by contrast-enhanced ultrasound (CEUS) at rest and during recovery from a bout of resistance exercise in older adults.nnMETHODS: Sixteen older adults (72 ± 6 y, 5/11 male/female) participated in an experimental test day during which a muscle biopsy was collected from the vastus lateralis and microvascular perfusion was determined by CEUS at rest and at 10 and 40 min following a bout of resistance exercise. Immunohistochemistry was performed on muscle tissue samples to determine various indices of both mixed and fiber-type-specific muscle fiber capillarization.nnRESULTS: Microvascular blood volume at t = 10 min was higher compared with rest and t = 40 min (27.2 ± 4.7 vs. 3.9 ± 4.0 and 7.0 ± 4.9 AU, respectively, both p < 0.001). Microvascular blood volume at t = 40 min was higher compared with rest (p < 0.001). No associations were observed between different indices of mixed muscle fiber capillarization and microvascular blood volume at rest and following exercise. A moderate (r = 0.59, p < 0.05) and strong (r = 0.81, p < 0.001) correlation was observed between type II muscle fiber capillary-to-fiber ratio and the microvascular blood volume increase from rest to t = 10 and t = 40 min, respectively. In addition, type II muscle fiber capillary contacts and capillary-to-fiber perimeter exchange index were strongly correlated with the microvascular blood volume increase from rest to t = 40 min (r = 0.66, p < 0.01 and r = 0.64, p < 0.01, respectively).nnCONCLUSION: Resistance exercise strongly increases microvascular blood volume for at least 40 min after exercise cessation in older adults. This resistance exercise-induced increase in microvascular blood volume is strongly associated with type II muscle fiber capillarization in older adults.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}