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The purpose of this research is to understand how chronic inflammation affects muscle function and responses to exercise in older adults.
This study will characterize intramuscular molecular mechanisms underlying anabolic resistance to protein ingestion during muscle disuse. Adults (n=12) will be studied using a unilateral leg immobilization model in which one leg will be randomly assigned to immobilization and the contralateral, active leg used as a within-subjects control. Immobilization will be implemented for five days using a rigid knee brace, during which time participants will ambulate using crutches. Integrated ribonucleic acid (RNA) synthesis will be determined during immobilization in the immobilized and non-immobilized legs using ingested deuterium oxide, salivary and blood sampling, and muscle biopsies. Immediately after immobilization, muscle biopsies will be collected before and 90 mins after consuming 25 g of whey protein from the immobilized and non-immobilized legs to characterize the intramuscular molecular response to protein feeding. Serial blood samples will be collected during that time to characterize the circulating metabolic response to protein ingestion. Knowledge generated from this effort will inform the development of targeted interventions for mitigating anabolic resistance to protein ingestion that develops during periods of muscle disuse.
The current study will determine protein nutritional status (MPS and WBPB) in response to military-relevant sleep loss, and whether an even protein nutrition distribution during recovery optimally supports MPS and WBPB. Adults (n=20) will complete a 7d sleep satiated phase (\~7-9h target/d), a 4d military-relevant sleep restriction phase (\~4h /d), and a 3d recovery phase (\~7-9h target/d) in a randomized, parallel design. During recovery, volunteers will consume 1.6 g protein/kg/d as an even (\~0.4/0.4/0.4/0.4 g/kg) or skewed (\~0.11/0.27/1.15/0.07 g/kg) distribution. Sleep will be monitored throughout the study using wrist actigraphy and diaries. During each phase, integrated daily MPS will be estimated using ingested deuterium oxide, salivary and blood sampling, and muscle biopsies, while WBPB will be estimated using ingested 15-N alanine and urine collections. At the end of each phase, metabolic testing will be used to assess the effects of sleep loss on substrate utilization and include consuming a carbohydrate beverage, serial blood draws, indirect calorimetry, and steady-state aerobic exercise. The knowledge products derived from the proposed effort will be informative to next generation ration development and support military-specific recovery nutrition guidance following operations involving sleep loss.
This study will be the first demonstration of the utility and feasibility of Phosphodiesterase Type 5 inhibitor as an effective pharmacological therapy for improving anabolic resistant states.
This is an interventional study enrolling older individuals aged 60-85y to observe changes during physical inactivity. This study is investigating the relation between short-term physical inactivity and the impact of muscle health and function. The enrollment goal is 8 participants. The study will occur over the course of a month where participants will undergo testing before and after a reduction in physically activity levels. There will be a screening event collecting baseline data, two body composition scans, muscle function and oral glucose tolerance tests and a metabolic study before and after a 2-week period of inactivity. Each metabolic study will entail three-muscle biopsies: one before and 2 after the ingestion of leucine.
The main goal of this study is to find out if supplementing with resveratrol improves skeletal muscle adaptations to strengthening exercise (resistance training or strength training) in adults age 60+, and to determine whether circulating vehicles of inter-organ communication (extracellular vesicles) and their cargo might help explain those responses. The investigators will also examine whether resveratrol supplementation improves blood vessel function and cognitive function (brain health) in response to strength training.
Individuals who sustain musculoskeletal injuries (MSKI) can experience a rapid loss of muscle mass due to declines in muscle loading and activation that occur post-injury (i.e., disuse atrophy). Loss of muscle under these conditions is attributed to a persistent negative net muscle protein balance (muscle protein synthesis \[MPS\] \< muscle protein breakdown) that results, in part, from declines in postprandial MPS (i.e., anabolic resistance). Nutritional interventions that enhance postprandial MPS may be used to overcome disuse-induced anabolic resistance and preserve muscle mass to accelerate recovery and improve recovery outcomes. While supplemental protein has been explored as a potential countermeasure to disuse-induce anabolic resistance, the observed efficacy of such interventions has been mixed. Equivocal findings across studies may be attributed, in part, to an insufficient understanding of what constitutes an effective protein-based intervention. Importantly, no study to date has determined an optimal protein dose for overcoming disuse-induce anabolic resistance, or if there is a threshold for maximally stimulating postprandial MPS under disuse conditions. Therefore, the objective of this work is to determine rates of MPS at rest and in response to standard (20 g) or high (40 g) doses of whey protein during knee immobilization (DISUSE) compared with standard activity (ACTIVE)
Sarcopenia is a predictor of functional-limitation, leading to loss of independence, lowered quality of life, and ultimately death. The impaired ability of aged skeletal muscle to adapt to anabolic stimulation may be a factor that contributes to sarcopenia. This project will provide novel insights into the role of microRNA in the attenuation of aging skeletal muscle to changes in gene expression after anabolic stimulation.
To examine the amino acid absorption following acute resistance exercise between three supplemental treatments: 1) Whey Protein + ProHydrolase (WPH) 2) Whey Protein (W) and 3) Non-Caloric Placebo (PL). To examine three supplemental treatments (WPH, W, PL) in conjunction with acute resistance exercise on the mTORC1 complex pathway. To examine three supplemental treatments (WPH, W, PL) in conjunction with acute resistance exercise on circulating concentrations of endocrine biomarkers.
The purpose of this study is to determine the effect of oxandrolone on the function and quality of life of patients with chronic spinal cord injury.