Medicine and Health Sciences Commons^™

Individual Responses For Muscle Activation, Repetitions, And Volume During Three Sets To Failure Of High- (80% 1rm) Versus Low-Load (30% 1rm) Forearm Flexion Resistance Exercise, Nathaniel D. M. Jenkins, Terry J. Housh, Samuel L. Buckner, Haley C. Bergstrom, Kristen C. Cochrane, Cory M. Smith, Ethan C. Hill, Richard J. Schmidt, Joel T. Cramer

Kinesiology and Health Promotion Faculty Publications

This study compared electromyographic (EMG) amplitude, the number of repetitions completed, and exercise volume during three sets to failure of high- (80% 1RM) versus low-load (30% 1RM) forearm flexion resistance exercise on a subject-by-subject basis. Fifteen men were familiarized, completed forearm flexion 1RM testing. Forty-eight to 72 h later, the subjects completed three sets to failure of dumbbell forearm flexion resistance exercise with 80% (n = 8) or 30% (n = 7) 1RM. EMG amplitude was calculated for every repetition, and the number of repetitions performed and exercise volume were recorded. During sets 1, 2, and 3, one …

Short-Term, High-Fat Diet Accelerates Disuse Atrophy And Protein Degradation In A Muscle-Specific Manner In Mice, Steven L. Roseno, Patrick R. Davis, Lance M. Bollinger, Jonathan J. S. Powell, Carol A. Witczak, Jeffrey J. Brault

Kinesiology and Health Promotion Faculty Publications

BACKGROUND: A short-term high-fat diet impairs mitochondrial function and the ability of skeletal muscle to respond to growth stimuli, but it is unknown whether such a diet alters the ability to respond to atrophy signals. The purpose of this study was to determine whether rapid weigh gain induced by a high-fat (HF) diet accelerates denervation-induced muscle atrophy.

METHODS: Adult, male mice (C57BL/6) were fed a control or HF (60 % calories as fat) diet for 3 weeks (3wHF). Sciatic nerve was sectioned unilaterally for the final 5 or 14 days of the diet. Soleus and extensor digitorum longus …

Less Is More: The Physiological Basis For Tapering In Endurance, Strength, And Power Athletes, Kevin A. Murach, James R. Bagley

Physical Therapy Faculty Publications

Taper, or reduced-volume training, improves competition performance across a broad spectrum of exercise modes and populations. This article aims to highlight the physiological mechanisms, namely in skeletal muscle, by which taper improves performance and provide a practical literature-based rationale for implementing taper in varied athletic disciplines. Special attention will be paid to strength- and power-oriented athletes as taper is under-studied and often overlooked in these populations. Tapering can best be summarized by the adage “less is more” because maintained intensity and reduced volume prior to competition yields significant performance benefits.

Immune Function And Muscle Adaptations To Resistance Exercise In Older Adults: Study Protocol For A Randomized Controlled Trial Of A Nutritional Supplement, Richard A. Dennis, Usha Ponnappan, Ralph L. Kodell, Kimberly K. Garner, Christopher M. Parkes, Melinda M. Bopp, Kalpana P. Padala, Charlotte A. Peterson, Prasad R. Padala, Dennis H. Sullivan

Physical Therapy Faculty Publications

BACKGROUND: Immune function may influence the ability of older adults to maintain or improve muscle mass, strength, and function during aging. Thus, nutritional supplementation that supports the immune system could complement resistance exercise as an intervention for age-associated muscle loss. The current study will determine the relationship between immune function and exercise training outcomes for older adults who consume a nutritional supplement or placebo during resistance training and post-training follow-up. The supplement was chosen due to evidence suggesting its ingredients [arginine (Arg), glutamine (Gln), and β-hydroxy β-methylbutyrate (HMB)] can improve immune function, promote muscle growth, and counteract muscle loss. …

Tumor-Derived Proteins And Mitochondrial Dysfunction In Lung Cancer-Induced Cachexia, Julie B. Mclean

Theses and Dissertations--Physiology

Lung tumors secrete multiple factors that contribute to cachexia, a severe wasting syndrome that includes loss of muscle mass, weakness, and fatigue. 80% of advanced lung cancer patients experience cachexia, which cannot be reversed by nutritional interventions, diminishes response to and tolerance of cancer treatments, and increases morbidity and mortality. Despite a multitude of clinical trials, there are currently no approved treatments. This deficiency suggests that not all of the factors that contribute to cachexia have been identified.

Cancer is frequently accompanied by an increase in cyclooxygenase-2 (COX-2), a hallmark of inflammation. Clinical trials for COX-2 inhibitors have resulted in …

Impaired Glucose Metabolism In The Absence Of Skeletal Muscle Brain And Muscle Arnt-Like-Protein 1 (Bmal1), Brianna D. Harfmann

Theses and Dissertations--Physiology

Metabolism is a critical physiological function that works to generate energy for cells, store substrates and maintain homoeostasis. Alterations in normal metabolism can have a severe effect on physiology, leading to metabolic disease. Skeletal muscle is a key metabolic tissue, taking up ~80% of postprandial glucose. Therefore it contributes considerably to glucose metabolism: glucose uptake, oxidation and homeostasis. To address the role of the skeletal muscle clock in insulin sensitivity and glucose tolerance, our lab generated an inducible skeletal muscle specific Bmal1^-/- mouse (iMSBmal1^-/-). 5 weeks post-recombination we observed impairment in both insulin- and AICAR-stimulated skeletal …

Global-Scale Analysis Of The Dynamic Transcriptional Adaptations Within Skeletal Muscle During Hypertrophic Growth, Tyler Kirby

Theses and Dissertations--Physiology

Skeletal muscle possesses remarkable plasticity in responses to altered mechanical load. An established murine model used to increase mechanical load on a muscle is the surgical removal of the gastrocnemius and soleus muscles, thereby placing a functional overload on the plantaris muscle. As a consequence, there is hypertrophic growth of the plantaris muscle. We used this model to study the molecular mechanisms regulating skeletal muscle hypertrophy.

Aged skeletal muscle demonstrates blunted hypertrophic growth in response to functional overload. We hypothesized that an alteration in gene expression would contribute to the blunted hypertrophic response observed with aging. However, the difference in …