View clinical trials related to Skeletal Muscle.
Filter by:The research project is aiming to examine the muscular adaptations to resistance training (RT), detraining (DT) and repeated RT (i.e. retraining). The research project will also examine differences in muscular adaptations between 20 weeks of continuous RT and 20 weeks of intermittent RT including a 10-week DT period in the middle of the training intervention. This is randomized controlled trial in which the research participants will be randomized into discontinuous and continuous groups (both n=~20). Both will be doing a 2-3-week familiarization and control period at the start. Then in the former there will be an initial strength training period (10-wks), a DT period (10-wks), and a second strength training (retraining) period (10-wks). The second group includes a 10-wk non-training control period (10-wks) followed by a RT period (20-wks). Participants will be young, healthy men and women (age 18-35, which 50% are females) with no systematic RT experience during the last 6 months. Measurements will be completed before and after each study period. Body composition will be measured via bioelectrical impedance analysis (BIA) and 3D body scans. Dynamic leg press and elbow flexion one repetition-maximum (1RM) will be used to test maximal strength. Anaerobic performance and strength endurance will be tested in elbow flexion and dynamic leg press using RM tests. Vastus lateralis (VL) and biceps brachii muscle cross-sectional area (CSA) will be assessed via ultrasound. Muscle biopsies of the VL muscle will be obtained to assess changes in muscle fiber morphology and factors regulating and associated with the hypertrophic processes and metabolism. Blood samples will be collected to analyze changes in metabolism and physiology. A rating of perceived exertion (RPE) during training will be collected after every exercise to ensure proper training intensity. Finally, nutrition and habitual physical activity will be assessed with 4-day diet diaries and physical activity questionnaires before the intervention and during each 10-week period.
Prolonged periods of reduced activity are associated with decreased vascular function and muscle atrophy. Physical inactivity due to a sedentary lifestyle or acute hospitalization is also associated with impaired recovery, hospital readmission, and increased mortality. Older adults are a particularly vulnerable population as functional (vascular and skeletal muscle mitochondrial dysfunction) and structural deficits (loss in muscle mass leading to a reduction in strength) are a consequence of the aging process. The combination of inactivity and aging poses an added health threat to these individuals by accelerating the negative impact on vascular and skeletal muscle function and dysfunction. The underlying factors leading to vascular and skeletal muscle dysfunction are unknown, but have been linked to increases in oxidative stress. Additionally, there is a lack of understanding of how vascular function is impacted by inactivity in humans and how these changes are related to skeletal muscle function. It is the goal of this study to investigate the mechanisms that contribute to disuse muscle atrophy and vascular dysfunction in order to diminish their negative impact, and preserve vascular and skeletal muscle function.
The purpose of this study is to assess which amino acids are affecting acute muscle collagen synthesis in response to supplementation and exercise.
Recently a common Greenlandic nonsense p.Arg684erTer variant (in which arginine is replaced by a termination codon) in the gene TBC1D4 was discovered. The variant has an allele frequency of 17%. Homozygous carriers of this TBC1D4 variant have impaired glucose tolerance and a 10-fold enhanced risk of developing type 2 diabetes (T2D). The investigators propose to carry out comprehensive metabolic phenotyping of adult Inuits carrying zero or two alleles of the TBC1D4 variant. The investigators hypothesise that regulation of TBC1D4 in skeletal muscle is pivotal in regulating glucose uptake during exercise, during physiological insulin stimulation, and for the ability of an acute bout of exercise to improve insulin sensitivity to regulate glucose metabolism in humans. The overall aims in the present project are to: 1. Determine whether the TBC1D4 p.Arg684Ter variant affects the regulation of glucose uptake in skeletal muscle during exercise and during physiological insulin stimulation. 2. Determine the effect of the TBC1D4 p.Arg684Ter variant for the ability of acute exercise to insulin sensitize skeletal muscle to regulate glucose metabolism. 3. Define the metabolic pathways affected by the p.Arg684Ter variant in order to identify causal factors responsible for the diabetic phenotype of Inuit carriers. The knowledge generated will contribute to additional explanatory clues to the increased frequency of T2D in the carriers.
To highlight the importance of protein quality rather than the total protein content of a meal, the investigators will demonstrate that unlike high quality proteins, a single meal containing 30 g of an incomplete protein source does not stimulate skeletal muscle protein synthesis. Secondly, the investigators will directly challenge a prevalent, but untested, assertion that has the potential to negatively impact health. The goal is to demonstrate that complementary plant-proteins (i.e., two or more incomplete protein sources) must be consumed at the same meal to stimulate protein synthesis.
The CHRONOS project aims to provide a device to detect earlier the motor decline, by developing a precise quantitative device measuring "Motor Functional Age" (MFA) of young, middle-aged and old people, thus preventing future functional motor loss for healthy aging. The MFA might be different from the Chronological Age (CA), depending on lifestyle, physical activity, and medical condition. Thus, this device will permit monitoring, adaptation and new design of a variety of personalized therapies for healthy aging including physical exercise, medication and nutritional interventions to reduce the MFA toward or less than the CA. The device combines data processing software that estimates the MFA by assessing muscle aging using a non-invasive multichannel electromyographical technique coupled to accelerometry sensors for motion evaluation. These data will provide with a built-in clinical database of subjects from different age categories (25-75 years old).
The purpose of this study was to determine the effects of L-leucine (LEU) or different protein supplements standardized to LEU (~3.0 g/serving) on changes in body composition, strength, and histological attributes in skeletal muscle and adipose tissue. Seventy-five untrained, college-aged males (mean±SE; age=21±1 yr, body mass=79.2±0.3 kg) were randomly assigned to an isocaloric, lipid-, and organoleptically-matched maltodextrin placebo (PLA, n=15), LEU (n=14), whey protein concentrate (WPC, n=17), whey protein hydrolysate (WPH, n=14), or soy protein concentrate (SPC, n=15) group. Participants performed whole-body resistance training three days per week for 12 weeks while consuming supplements twice daily. Skeletal muscle and subcutaneous (SQ) fat biopsies were obtained at baseline (T1) and ~72 h following the last day of training (T39). Tissue samples were analyzed for changes in type I and II fiber cross sectional area (CSA), non-fiber specific satellite cell count, and SQ adipocyte CSA. On average, all supplement groups including PLA exhibited similar training volumes and experienced statistically similar increases in total body skeletal muscle mass determined by dual x-ray absorptiometry (+2.2 kg; time p=0.024) and type I and II fiber CSA increases (+394 µm2 and +927 µm2; time p<0.001 and 0.024, respectively). Notably, all groups reported increasing Calorie intakes ~600-800 kcal/d from T1 to T39 (time p<0.001), and all groups consumed at least 1.1 g/kg/d of protein at T1 and 1.3 g/kg/d at T39. There was a training, but no supplementation, effect regarding the reduction in SQ adipocyte CSA (-210 µm2; time p=0.001). Interestingly, satellite cell counts within the WPC (p<0.05) and WPH (p<0.05) groups were greater at T39 relative to T1. In summary, LEU or protein supplementation (standardized to LEU content) does not provide added benefit in increasing whole-body skeletal muscle mass or strength above PLA following 3 months of training in previously untrained college-aged males that increase Calorie intakes with resistance training and consume above the recommended daily intake of protein throughout training. However, whey protein supplementation increases skeletal muscle satellite cell number in this population, and this phenomena may promote more favorable training adaptations over more prolonged periods.
The investigator showed that a night of sleep deprivation halved the duration of an inspiratory endurance test and that this loss of endurance could be secondary to a lack of activation of the pre-motor cortex. However, the inspiratory endurance test is associated with a feeling of dyspnea that could lead to premature arrest, and the inspiratory drive is complex, both automatic and voluntary. The investigator can reproduce this results on a simpler drive. During the execution of an exercise involving repeated contractions of the hand it is possible to record the activation of the pre-motor cortex corresponding to the phase of preparation of the movement. The amplitude of these premotor potentials is proportional to the developed motive force. The purpose of this study is to assess the impact of sleep deprivation on the muscular endurance of non-dominant in healthy subjects. Hypothesis: Sleep deprivation causes a decrease in manual motor endurance by decreasing cortical pre-motor control. Main objective: To compare the motor endurance of healthy subjects after a night's sleep and after a sleepless night. Secondary objective: To compare the amplitude of premature cortical control at the beginning of the endurance test after a night's sleep and after a sleepless night.
The purpose of this Proof of Concept study is to determine the effects of BYM338 on skeletal muscle volume, mass, and strength and patient function (gait speed) in non-demented elderly adults with sarcopenia and mobility limitations. In addition, this study will generate data on the safety, tolerability, and pharmacokinetics of BYM338 in older adults and its response on additional physical function measures in this population. Furthermore, the extended study duration will provide information on the stability of BYM-induced changes in skeletal muscle and patient function in this subgroup of the older population.
The investigators here propose to perform a prospective randomized intervention trial in post-menopausal women to investigate the endocrine network, which contributes to the changes in skeletal muscle mass during weight loss.