ORCID Profile
0000-0002-6427-1067
Current Organisation
Central Queensland University
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Publisher: Informa UK Limited
Date: 29-05-2018
Publisher: Elsevier BV
Date: 08-2019
DOI: 10.1016/J.JSAMS.2019.03.009
Abstract: To determine if a 4 d period of high carbohydrate intake can supercompensate muscle glycogen and exercise work capacity on back-to-back occasions. Seven trained cyclists (6 male, VO A resting muscle biopsy was obtained prior to each trial consisting of 2 min work intervals (90-60% peak power output) interspersed with 2 min recovery (40% peak power output) repeated until exhaustion. Each 72-h period between trial days included two days of low volume cycling and a rest day. Resting muscle glycogen and total work completed was determined for each trial day. Baseline muscle glycogen on day 1 (583.6 ± 111.0 mmol kg A 4 d high carbohydrate feeding strategy is sufficient to repeatedly supercompensate muscle glycogen content following exhaustive exercise and results in enhanced work capacity.
Publisher: Human Kinetics
Date: 05-2020
Abstract: Purpose : Due to age-related changes in the psychobiological state of masters athletes, this brief report aimed to compare training load responses using heart rate (HR) and ratings of perceived exertion (RPE) during standardized training sessions between masters and young cyclists. Methods : Masters (n = 10 55.6 [5.0] y) and young (n = 8 25.9 [3.0] y) cyclists performed separate endurance and high-intensity interval training sessions. Endurance intensity was set at 95% of ventilatory threshold 2 for 1 hour. High-intensity interval training consisted of 6 × 30-second intervals at 175% peak power output with 4.5-minute rest between intervals. HR was monitored continuously and RPE collected at standardized time periods during each session. Banister training impulse and summated-HR-zones training loads were also calculated. Results : Despite a significantly lower mean HR in masters cyclists during endurance ( P = .04 d = 1.06 [±0.8], moderate) and high-intensity interval training ( P = .01 d = 1.34 [±0.8], large), no significant differences were noted ( P .05) when responses were determined relative to maximum HR or converted to training impulse and summated-HR-zone loads. Furthermore, no interaction or between-group differences were evident for RPE across either session ( P .05). Conclusions : HR and RPE values were comparable between masters and young cyclists when relative HR responses and HR training load models are used. This finding suggests HR and RPE methods used to monitor or prescribe training load can be used interchangeably between masters and young athletes irrespective of chronological age.
Publisher: Wiley
Date: 30-06-2021
DOI: 10.1002/JCSM.12741
Abstract: Knowledge of age‐related DNA methylation changes in skeletal muscle is limited, yet this tissue is severely affected by ageing in humans. We conducted a large‐scale epigenome‐wide association study meta‐analysis of age in human skeletal muscle from 10 studies (total n = 908 muscle methylomes from men and women aged 18–89 years old). We explored the genomic context of age‐related DNA methylation changes in chromatin states, CpG islands, and transcription factor binding sites and performed gene set enrichment analysis. We then integrated the DNA methylation data with known transcriptomic and proteomic age‐related changes in skeletal muscle. Finally, we updated our recently developed muscle epigenetic clock ( ackages/release/bioc/html/MEAT.html ). We identified 6710 differentially methylated regions at a stringent false discovery rate .005, spanning 6367 unique genes, many of which related to skeletal muscle structure and development. We found a strong increase in DNA methylation at Polycomb target genes and bivalent chromatin domains and a concomitant decrease in DNA methylation at enhancers. Most differentially methylated genes were not altered at the mRNA or protein level, but they were nonetheless strongly enriched for genes showing age‐related differential mRNA and protein expression. After adding a substantial number of s les from five datasets (+371), the updated version of the muscle clock (MEAT 2.0, total n = 1053 s les) performed similarly to the original version of the muscle clock (median of 4.4 vs. 4.6 years in age prediction error), suggesting that the original version of the muscle clock was very accurate. We provide here the most comprehensive picture of DNA methylation ageing in human skeletal muscle and reveal widespread alterations of genes involved in skeletal muscle structure, development, and differentiation. We have made our results available as an open‐access, user‐friendly, web‐based tool called MetaMeth ( sarah‐voisin.shinyapps.io/MetaMeth/ ).
Publisher: Human Kinetics
Date: 11-2020
Abstract: Context : Exercise in hot environments increases body temperature and thermoregulatory strain. However, little is known regarding the magnitude of effect that ambient temperature ( T a ), relative humidity (RH), and solar radiation in idually have on team-sport athletes. Purpose : To determine the effect of these in idual heat-stress variables on team-sport training performance and recovery. Methods : Professional Australian Rules Football players (N = 45) undertook 8-wk preseason training producing a total of 579 outdoor field-based observations with T a , RH, and solar radiation recorded at every training session. External load (distance covered, in m/min percentage high-speed running [%HSR] .4 km/h) was collected via a global positioning system. Internal load (ratings of perceived exertion and heart rate) and recovery (subjective ratings of well-being and heart-rate variability [root mean square of the successive differences]) were monitored throughout the training period. Mixed-effects linear models analyzed relationships between variables using standardized regression coefficients. Results : Increased solar-radiation exposure was associated with reduced distance covered (−19.7 m/min, P .001), %HSR (−10%, P .001) during training and rMSSD 48 h posttraining (−16.9 ms, P = .019). Greater RH was associated with decreased %HSR (−3.4%, P = .010) but increased percentage duration % HR max (3.9%, P .001), ratings of perceived exertion (1.8 AU, P .001), and self-reported stress 24 h posttraining (−0.11 AU, P = .002). In contrast, higher T a was associated with increased distance covered (19.7 m/min, P .001) and %HSR (3.5%, P = .005). Conclusions : The authors show the importance of considering the in idual factors contributing to thermal load in isolation for team-sport athletes and that solar radiation and RH reduce work capacity during team-sport training and have the potential to slow recovery between sessions.
Publisher: Cold Spring Harbor Laboratory
Date: 28-09-2020
DOI: 10.1101/2020.09.28.315838
Abstract: Knowledge of age-related DNA methylation changes in skeletal muscle is limited, yet this tissue is severely affected by aging in humans. Using a large-scale epigenome-wide association study (EWAS) meta-analysis of age in human skeletal muscle from 10 studies (total n = 908 human muscle methylomes), we identified 9,986 differentially methylated regions at a stringent false discovery rate 0.005, spanning 8,748 unique genes, many of which related to skeletal muscle structure and development. We then integrated the DNA methylation results with known transcriptomic and proteomic age-related changes in skeletal muscle, and found that even though most differentially methylated genes are not altered at the mRNA or protein level, they are nonetheless strongly enriched for genes showing age-related differential expression. We provide here the most comprehensive picture of DNA methylation aging in human skeletal muscle, and have made our results available as an open-access, user-friendly, web-based tool called MetaMeth ( sarah-voisin.shinyapps.io/MetaMeth/ ).
Publisher: BMJ
Date: 03-2019
DOI: 10.1136/BJSPORTS-2018-099889
Abstract: To determine the effects of multi-ingredient protein (MIP) supplements on resistance exercise training (RT)-induced gains in muscle mass and strength compared with protein-only (PRO) or placebo supplementation. Systematic search of MEDLINE, Embase, CINAHL and SPORTDiscus. Randomised controlled trials with interventions including RT ≥6 weeks in duration and a MIP supplement. Random effects meta-analyses were conducted to determine the effect of supplementation on fat-free mass (FFM), fat mass, one-repetition maximum (1RM) upper body and 1RM lower body muscular strength. Subgroup analyses compared the efficacy of MIP supplementation relative to training status and chronological age. The most common MIP supplements included protein with creatine (n=17) or vitamin D (n=10). Data from 35 trials with 1387 participants showed significant (p .05) increases in FFM (0.80 kg (95% CI 0.44 to 1.15)), 1RM lower body (4.22 kg (95% CI 0.79 to 7.64)) and 1RM upper body (2.56 kg (95% CI 0.79 to 4.33)) where a supplement was compared with all non-MIP supplemented conditions (means (95% CI)). Subgroup analyses indicated a greater effect of MIP supplements compared with all non-MIP supplements on FFM in untrained (0.95 kg (95% CI 0.51 to 1.39), p .0001) and older participants (0.77 kg (95% CI 0.11 to 1.43), p=0.02) taking MIP supplements was also associated with gains in 1RM upper body (1.56 kg (95% CI 0.80 to 2.33), p=0.01) in older adults. When MIP supplements were combined with resistance exercise training, there were greater gains in FFM and strength in healthy adults than in counterparts who were supplemented with non-MIP. MIP supplements were not superior when directly compared with PRO supplements. The magnitude of effect of MIP supplements was greater (in absolute values) in untrained and elderly in iduals undertaking RT than it was in trained in iduals and in younger people. CRD42017081970.
Publisher: Informa UK Limited
Date: 12-07-2019
Publisher: Canadian Science Publishing
Date: 05-2023
Abstract: We aimed to determine whether there was a relationship between pre-immobilization skeletal muscle size and the magnitude of muscle atrophy following 14 days of unilateral lower limb immobilization. Our findings ( n = 30) show that pre-immobilization leg fat-free mass and quadriceps cross-sectional area (CSA) were unrelated to the magnitude of muscle atrophy. However, sex-based differences may be present, but confirmatory work is required. In women, pre-immobilization leg fat-free mass and CSA were associated with changes in quadriceps CSA after immobilization ( n = 9, r 2 = 0.54–0.68 P 0.05). The extent of muscle atrophy is not affected by initial muscle mass, but there is potential for sex-based differences.
Publisher: Wiley
Date: 02-05-2023
DOI: 10.1111/ACEL.13859
Abstract: Exercise training prevents age‐related decline in muscle function. Targeting epigenetic aging is a promising actionable mechanism and late‐life exercise mitigates epigenetic aging in rodent muscle. Whether exercise training can decelerate, or reverse epigenetic aging in humans is unknown. Here, we performed a powerful meta‐analysis of the methylome and transcriptome of an unprecedented number of human skeletal muscle s les ( n = 3176). We show that: (1) in iduals with higher baseline aerobic fitness have younger epigenetic and transcriptomic profiles, (2) exercise training leads to significant shifts of epigenetic and transcriptomic patterns toward a younger profile, and (3) muscle disuse “ages” the transcriptome. Higher fitness levels were associated with attenuated differential methylation and transcription during aging. Furthermore, both epigenetic and transcriptomic profiles shifted toward a younger state after exercise training interventions, while the transcriptome shifted toward an older state after forced muscle disuse. We demonstrate that exercise training targets many of the age‐related transcripts and DNA methylation loci to maintain younger methylome and transcriptome profiles, specifically in genes related to muscle structure, metabolism, and mitochondrial function. Our comprehensive analysis will inform future studies aiming to identify the best combination of therapeutics and exercise regimes to optimize longevity.
Publisher: Elsevier BV
Date: 10-2017
Abstract: Disparities in health perspectives between Indigenous and non-Indigenous populations are major concerns in many of the world's well-developed nations. Indigenous populations are largely less healthy, more prone to chronic diseases, and have an earlier overall mortality than non-Indigenous populations. Low levels of physical activity (PA) contribute to the high levels of disease in Indigenous Australians. Qualitative analysis of structured one-on-one interviews discussing PA in a regional setting. Participants were 12 Indigenous Australian adults, and 12 non-Indigenous Australian adults matched on age, sex, and basketball ision. Most participants reported engaging in regular exercise however, the Indigenous group reported more barriers to PA. These factors included cost, time management and environmental constraints. The physical facilitators identified by our Indigenous s le included social support, intrinsic motivation and role modelling. Findings describe in idual and external factors that promote or constraint PA as reported by Indigenous Australian adults. Results indicate that Indigenous people face specific barriers to PA when compared to a non-Indigenous s le. Implications for public health: This study is the first to compare the perspective of Indigenous Australians to a matched group of non-Indigenous Australians and provides useful knowledge to develop public health programs based on culturally sensitive data.
Publisher: Human Kinetics
Date: 02-2017
Abstract: Following exercise-induced muscle damage (EIMD), masters athletes take longer to recover than younger athletes. The purpose of this study was to determine the effect of higher than recommended postexercise protein feedings on the recovery of knee extensor peak isometric torque (PIT), perceptions of recovery, and cycling time trial (TT) performance following EIMD in masters triathletes. Eight masters triathletes (52 ± 2 y, V̇O 2max , 51.8 ± 4.2 ml•kg -1 •min -1 ) completed two trials separated by seven days in a randomized, doubleblind, crossover study. Trials consisted of morning PIT testing and a 30-min downhill run followed by an eight-hour recovery. During recovery, a moderate (MPI 0.3 g•kg -1 •bolus -1 ) or high (0.6 g•kg -1 •bolus -1 ) protein intake (HPI) was consumed in three bolus feedings at two hour intervals commencing immediately postexercise. PIT testing and a 7 kJ•kg -1 cycling TT were completed postintervention. Perceptions of recovery were assessed pre- and postexercise. The HPI did not significantly improve recovery compared with MPI ( p .05). However, comparison of within-treatment change shows the HPI provided a moderate beneficial effect ( d = 0.66), attenuating the loss of afternoon PIT (-3.6%, d = 0.09) compared with the MPI (-8.6%, d = 0.24). The HPI provided a large beneficial effect ( d = 0.83), reducing perceived fatigue over the eight-hour recovery ( d = 1.25) compared with the MPI ( d = 0.22). Despite these effects, cycling performance was unchanged (HPI = 2395 ± 297 s vs. MPI = 2369 ± 278 s d = 0.09). In conclusion, doubling the recommended postexercise protein intake did not significantly improve recovery in masters athletes however, HPI provided moderate to large beneficial effects on recovery that may be meaningful following EIMD.
Publisher: Wiley
Date: 05-02-2021
DOI: 10.1113/EP089301
Abstract: What is the central question of this study? The extent to which genetics determines adaptation to endurance versus resistance exercise is unclear. Previously, a ergent selective breeding rat model showed that genetic factors play a major role in the response to aerobic training. Here, we asked: do genetic factors that underpin poor adaptation to endurance training affect adaptation to functional overload? What is the main finding and its importance? Our data show that heritable factors in low responders to endurance training generated differential gene expression that was associated with impaired skeletal muscle hypertrophy. A maladaptive genotype to endurance exercise appears to dysregulate biological processes responsible for mediating exercise adaptation, irrespective of the mode of contraction stimulus. Divergent skeletal muscle phenotypes result from chronic resistance‐type versus endurance‐type contraction, reflecting the principle of training specificity. Our aim was to determine whether there is a common set of genetic factors that influence skeletal muscle adaptation to ergent contractile stimuli. Female rats were obtained from a genetically heterogeneous rat population and were selectively bred from high responders to endurance training (HRT) or low responders to endurance training (LRT n = 6/group generation 19). Both groups underwent 14 days of synergist ablation to induce functional overload of the plantaris muscle before comparison to non‐overloaded controls of the same phenotype. RNA sequencing was performed to identify Gene Ontology biological processes with differential (LRT vs. HRT) gene set enrichment. We found that running distance, determined in advance of synergist ablation, increased in response to aerobic training in HRT but not LRT (65 ± 26 vs. −6 ± 18%, mean ± SD, P 0.0001). The hypertrophy response to functional overload was attenuated in LRT versus HRT (20.1 ± 5.6 vs. 41.6 ± 16.1%, P = 0.015). Between‐group differences were observed in the magnitude of response of 96 upregulated and 101 downregulated pathways. A further 27 pathways showed contrasting upregulation or downregulation in LRT versus HRT in response to functional overload. I n conclusion, low responders to aerobic endurance training were also low responders for compensatory hypertrophy, and attenuated hypertrophy was associated with differential gene set regulation. Our findings suggest that genetic factors that underpin aerobic training maladaptation might also dysregulate the transcriptional regulation of biological processes that contribute to adaptation to mechanical overload.
Publisher: Cold Spring Harbor Laboratory
Date: 11-11-2019
DOI: 10.1101/821009
Abstract: Ageing is associated with DNA methylation changes in all human tissues, and epigenetic markers can estimate chronological age based on DNA methylation patterns across tissues. However, the construction of the original pan-tissue epigenetic clock did not include skeletal muscle s les, and hence exhibited a strong deviation between DNA methylation and chronological age in this tissue. To address this, we developed a more accurate, muscle-specific epigenetic clock based on the genome-wide DNA methylation data of 682 skeletal muscle s les from 12 independent datasets (18-89 years old, 22% women, 99% Caucasian), all generated with Illumina HumanMethylation arrays (HM27, HM450 or HMEPIC). We also took advantage of the large number of s les to conduct an epigenome-wide association study (EWAS) of age-associated DNA methylation patterns in skeletal muscle. The newly developed clock uses 200 CpGs to estimate chronological age in skeletal muscle, 16 of which are in common with the 353 CpGs of the pan-tissue clock. The muscle clock outperformed the pan-tissue clock, with a median error of only 4.6 years across datasets ( vs 13.1 years for the pan-tissue clock, p 0.0001) and an average correlation of ρ = 0.62 between actual and predicted age across datasets ( vs ρ = 0.51 for the pan-tissue clock). Lastly, we identified 180 differentially methylated regions (DMRs) with age in skeletal muscle at a False Discovery Rate 0.005. However, Gene Set Enrichment Analysis did not reveal any enrichment for Gene Ontologies. We have developed a muscle-specific epigenetic clock that predicts age with better accuracy than the pan-tissue clock. We implemented the muscle clock in an R package called MEAT available on Bioconductor to estimate epigenetic age in skeletal muscle s les. This clock may prove valuable in assessing the impact of environmental factors, such as exercise and diet, on muscle-specific biological ageing processes.
Publisher: Springer Science and Business Media LLC
Date: 02-02-2017
DOI: 10.1007/S10286-017-0398-6
Abstract: This study aimed at examining the autonomic cardiovascular modulation in well-trained masters and young cyclists following high-intensity interval training (HIT). Nine masters (age 55.6 ± 5.0 years) and eight young cyclists (age 25.9 ± 3.0 years) completed a HIT protocol of 6 x 30 sec at 175% of peak power output, with 4.5-min' rest between efforts. Immediately following HIT, heart rate and R-R intervals were monitored for 30-min during passive supine recovery. Autonomic modulation was examined by i) heart rate recovery in the first 60-sec of recovery (HRR No significant between-group differences were observed for HRR Following high-intensity interval training, master cyclists demonstrated greater post-exercise parasympathetic reactivation compared to young cyclists, indicating that physical training at older ages has significant effects on autonomic function.
Publisher: Public Library of Science (PLoS)
Date: 09-2022
DOI: 10.1371/JOURNAL.PONE.0273925
Abstract: Skeletal muscle unloading due to joint immobilization induces muscle atrophy, which has primarily been attributed to reductions in protein synthesis in humans. However, no study has evaluated the skeletal muscle proteome response to limb immobilization using SWATH proteomic methods. This study characterized the shifts in in idual muscle protein abundance and corresponding gene sets after 3 and 14 d of unilateral lower limb immobilization in otherwise healthy young men. Eighteen male participants (25.4 ±5.5 y, 81.2 ±11.6 kg) underwent 14 d of unilateral knee-brace immobilization with dietary provision and following four-weeks of training to standardise acute training history. Participant phenotype was characterized before and after 14 days of immobilization, and muscle biopsies were obtained from the vastus lateralis at baseline (pre-immobilization) and at 3 and 14 d of immobilization for analysis by SWATH-MS and subsequent gene-set enrichment analysis (GSEA). Immobilization reduced vastus group cross sectional area (-9.6 ±4.6%, P .0001), immobilized leg lean mass (-3.3 ±3.9%, P = 0.002), unilateral 3-repetition maximum leg press (-15.6 ±9.2%, P .0001), and maximal oxygen uptake (-2.9 ±5.2%, P = 0.044). SWATH analyses consistently identified 2281 proteins. Compared to baseline, two and 99 proteins were differentially expressed (FDR .05) after 3 and 14 d of immobilization, respectively. After 14 d of immobilization, 322 biological processes were different to baseline (FDR .05, P 0.001). Most (77%) biological processes were positively enriched and characterized by cellular stress, targeted proteolysis, and protein-DNA complex modifications. In contrast, mitochondrial organization and energy metabolism were negatively enriched processes. This study is the first to use data independent proteomics and GSEA to show that unilateral lower limb immobilization evokes mitochondrial dysfunction, cellular stress, and proteolysis. Through GSEA and network mapping, we identify 27 hub proteins as potential protein/gene candidates for further exploration.
Publisher: BMJ
Date: 14-09-2016
Publisher: Wiley
Date: 17-02-2020
DOI: 10.1002/JCSM.12556
Publisher: Society for Transparency, Openness, and Replication in Kinesiology
Date: 26-01-2023
DOI: 10.51224/SRXIV.249
Publisher: Human Kinetics
Date: 04-2016
Abstract: Participation rates of masters athletes in endurance events such as long-distance triathlon and running continue to increase. Given the physical and metabolic demands of endurance training, recovery practices influence the quality of successive training sessions and, consequently, adaptations to training. Research has suggested that, after muscle-damaging endurance exercise, masters athletes experience slower recovery rates in comparison with younger, similarly trained athletes. Given that these discrepancies in recovery rates are not observed after non–muscle-damaging exercise, it is suggested that masters athletes have impairments of the protein remodeling mechanisms within skeletal muscle. The importance of postexercise protein feeding for endurance athletes is increasingly being acknowledged, and its role in creating a positive net muscle protein balance postexercise is well known. The potential benefits of postexercise protein feeding include elevating muscle protein synthesis and satellite cell activity for muscle repair and remodeling, as well as facilitating muscle glycogen resynthesis. Despite extensive investigation into age-related anabolic resistance in sedentary aging populations, little is known about how anabolic resistance affects postexercise muscle protein synthesis and thus muscle remodeling in aging athletes. Despite evidence suggesting that physical training can attenuate but not eliminate age-related anabolic resistance, masters athletes are currently recommended to consume the same postexercise dietary protein dose (approximately 20 g or 0.25 g/kg/meal) as younger athletes. Given the slower recovery rates of masters athletes after muscle-damaging exercise, which may be due to impaired muscle remodeling mechanisms, masters athletes may benefit from higher doses of postexercise dietary protein, with particular attention directed to the leucine content of the postexercise bolus.
Publisher: Human Kinetics
Date: 08-2016
Abstract: Postexercise nutrition is a critical component of an athlete’s recovery from training and competition. However, little is known about athletes’ postexercise dietary practices or knowledge of dietary recommendations, particularly among masters athletes. The purpose of this study was to compare and contrast the knowledge of postexercise nutritional recommendations, and typical postexercise intakes of carbohydrate and protein, between masters and younger triathletes. 182 triathletes (Male = 101, Female = 81) completed an online survey distributed by Triathlon Australia . Knowledge of postexercise nutrition recommendations for protein and carbohydrate intake were assessed as a group, and contrasted between subgroups of masters (≥50 years) and younger triathletes (≤30 years). Using dietary recall, postexercise intakes of carbohydrate and protein were examined and contrasted between masters and younger triathletes. As a group, 43.1% and 43.9% of all triathletes answered, “I don’t know” when asked to identify the recommended postexercise carbohydrate and protein intakes, respectively. Dietary analysis revealed masters triathletes consumed significantly less carbohydrate (0.7 ± 0.4 g.kg -1 ) postexercise than recommended (1.0 g.kg -1 p = .001), and in comparison with younger triathletes (1.1 ± 0.6 g.kg -1 p = .01). Postexercise protein intakes were similar between masters (19.6 ± 13.5 g) and younger (26.4 ± 15.8 g) triathletes. However, relative to body mass, masters triathletes consumed significantly less protein (0.3 ± 0.2 g.kg -1 ) than younger triathletes (0.4 ± 0.2 g.kg -1 p = .03), and consumed significantly less energy postexercise (22.7 ± 11.7 kJ.kg -1 ) than younger triathletes (37.8 ± 19.2 kJ.kg -1 p = .01). The present data suggests triathletes have poor knowledge of recommendations for postexercise carbohydrate and protein intakes. Furthermore, low postexercise intakes of carbohydrate and protein by masters athletes may impair acute recovery.
Publisher: BMJ
Date: 03-2019
DOI: 10.1136/BJSPORTS-2018-099889
Abstract: To determine the effects of multi-ingredient protein (MIP) supplements on resistance exercise training (RT)-induced gains in muscle mass and strength compared with protein-only (PRO) or placebo supplementation. Systematic search of MEDLINE, Embase, CINAHL and SPORTDiscus. Randomised controlled trials with interventions including RT ≥6 weeks in duration and a MIP supplement. Random effects meta-analyses were conducted to determine the effect of supplementation on fat-free mass (FFM), fat mass, one-repetition maximum (1RM) upper body and 1RM lower body muscular strength. Subgroup analyses compared the efficacy of MIP supplementation relative to training status and chronological age. The most common MIP supplements included protein with creatine (n=17) or vitamin D (n=10). Data from 35 trials with 1387 participants showed significant (p .05) increases in FFM (0.80 kg (95% CI 0.44 to 1.15)), 1RM lower body (4.22 kg (95% CI 0.79 to 7.64)) and 1RM upper body (2.56 kg (95% CI 0.79 to 4.33)) where a supplement was compared with all non-MIP supplemented conditions (means (95% CI)). Subgroup analyses indicated a greater effect of MIP supplements compared with all non-MIP supplements on FFM in untrained (0.95 kg (95% CI 0.51 to 1.39), p .0001) and older participants (0.77 kg (95% CI 0.11 to 1.43), p=0.02) taking MIP supplements was also associated with gains in 1RM upper body (1.56 kg (95% CI 0.80 to 2.33), p=0.01) in older adults. When MIP supplements were combined with resistance exercise training, there were greater gains in FFM and strength in healthy adults than in counterparts who were supplemented with non-MIP. MIP supplements were not superior when directly compared with PRO supplements. The magnitude of effect of MIP supplements was greater (in absolute values) in untrained and elderly in iduals undertaking RT than it was in trained in iduals and in younger people. CRD42017081970.
Publisher: Elsevier BV
Date: 08-2022
Publisher: Public Library of Science (PLoS)
Date: 13-01-2022
DOI: 10.1371/JOURNAL.PONE.0261723
Abstract: Skeletal muscle atrophy is a physiological response to disuse, aging, and disease. We compared changes in muscle mass and the transcriptome profile after short-term immobilization in a ergent model of high and low responders to endurance training to identify biological processes associated with the early atrophy response. Female rats selectively bred for high response to endurance training (HRT) and low response to endurance training (LRT n = 6/group generation 19) underwent 3 day hindlimb cast immobilization to compare atrophy of plantaris and soleus muscles with line-matched controls (n = 6/group). RNA sequencing was utilized to identify Gene Ontology Biological Processes with differential gene set enrichment. Aerobic training performed prior to the intervention showed HRT improved running distance (+60.6 ± 29.6%), while LRT were unchanged (-0.3 ± 13.3%). Soleus atrophy was greater in LRT vs. HRT (-9.0 ±8.8 vs. 6.2 ±8.2% P .05) and there was a similar trend in plantaris (-16.4 ±5.6% vs. -8.5 ±7.4% P = 0.064). A total of 140 and 118 biological processes were differentially enriched in plantaris and soleus muscles, respectively. Soleus muscle exhibited ergent LRT and HRT responses in processes including autophagy and immune response. In plantaris, processes associated with protein ubiquitination, as well as the atrogenes ( Trim63 and Fbxo32 ), were more positively enriched in LRT. Overall, LRT demonstrate exacerbated atrophy compared to HRT, associated with differential gene enrichments of biological processes. This indicates that genetic factors that result in ergent adaptations to endurance exercise, may also regulate biological processes associated with short-term muscle unloading.
Publisher: Termedia Sp. z.o.o.
Date: 2023
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 08-2016
Publisher: Human Kinetics
Date: 02-2014
Abstract: The purpose of this study was to investigate if acute caffeine exposure via mouth-rinse improved endurance cycling time-trial performance in well-trained cyclists. It was hypothesized that caffeine exposure at the mouth would enhance endurance cycling time-trial performance. Ten well-trained male cyclists (mean± SD : 32.9 ± 7.5 years, 74.7 ± 5.3kg, 176.8 ± 5.1cm, VO 2peak = 59.8 ± 3.5ml·kg–1·min–1) completed two experimental timetrials following 24 hr of dietary and exercise standardization. A randomized, double-blind, placebo-controlled, cross-over design was employed whereby cyclists completed a time-trial in the fastest time possible, which was equivalent work to cycling at 75% of peak aerobic power output for 60 min. Cyclists were administered 25ml mouth-rinses for 10 s containing either placebo or 35mg of anhydrous caffeine eight times throughout the time-trial. Perceptual and physiological variables were recorded throughout. No significant improvement in time-trial performance was observed with caffeine (3918 ± 243s) compared with placebo mouth-rinse (3940 ± 227s). No elevation in plasma caffeine was detected due to the mouth-rinse conditions. Caffeine mouth-rinse had no significant effect on rating of perceived exertion, heart rate, rate of oxygen consumption or blood lactate concentration. Eight exposures of a 35 mg dose of caffeine at the buccal cavity for 10s does not significantly enhance endurance cycling time-trial performance, nor does it elevate plasma caffeine concentration.
Publisher: Mary Ann Liebert Inc
Date: 12-2020
No related grants have been discovered for Thomas Michael Doering.