Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 15 of 15
Full-Text Articles in Physiology
Role Of Fat Content On The Structure And Function Of Human Skeletal Muscle, Joseph A. Gordon Iii
Role Of Fat Content On The Structure And Function Of Human Skeletal Muscle, Joseph A. Gordon Iii
Doctoral Dissertations
Muscle size does not fully explain variations in muscle strength. Fat content has been implicated in muscle weakness, though this relationship remains unclear. The relationship between fat and strength may vary between scales (e.g., cellular, organ, and organism). The goal of this dissertation was to clarify the role of fat in the structure and function of muscle using in vitro and in vivo techniques across multiple scales in adults 21-45 years old. Study 1 tested the agreement of intramyocellular lipid (IMCL) content between oil red o (ORO) and magnetic resonance spectroscopy (MRS) techniques. These measures of IMCL were also compared …
Beyond The Fat: Protein Metabolism And Muscle Function As Part Of The Migratory Syndrome Of Songbirds, Cory R. Elowe
Beyond The Fat: Protein Metabolism And Muscle Function As Part Of The Migratory Syndrome Of Songbirds, Cory R. Elowe
Doctoral Dissertations
Migration allows animals to seasonally exploit favorable habitats that are geographically disparate, and migratory animals have a suite of adaptations to complete their extraordinary journeys. This “migratory syndrome” of traits is comprised of seasonally-responsive adaptations that together result in changes to metabolism, body composition, and reproductive status, all of which act to increase the probability of a successful migration. The focus of my dissertation is to investigate the suite of changes in metabolism and muscle function that enable birds to undertake long-duration flights. In chapter 1, I compare fuel use in flight between two related migratory warbler species that migrate …
Link Between Muscle And Whole-Body Energetic Responses To Exercise, Christopher M.T. Hayden
Link Between Muscle And Whole-Body Energetic Responses To Exercise, Christopher M.T. Hayden
Masters Theses
Substantial evidence exists regarding how skeletal muscles use energy and how this affects muscular performance. What remains unclear is how characteristics of muscle energetics affect whole-body energetics during daily living, and what effects this may have on mobility. The goal of this study was to determine the associations between muscle and whole-body energetics including the relationships between: 1) muscle PCr depletion (∆PCr) in response to light intensity isotonic contractions and the oxygen deficit at the onset of a 30-min treadmill walk (30MTW), and, 2) muscle oxidative capacity and excess post-exercise oxygen consumption (EPOC; 30MTW), respiratory exchange ratio (RER; 30MTW), and …
Establishing And Validating Methods To Assess The Influence Of Exercise On Circulating Exosome Profiles In Sedentary Older Adults, Heather Quiriarte
Establishing And Validating Methods To Assess The Influence Of Exercise On Circulating Exosome Profiles In Sedentary Older Adults, Heather Quiriarte
LSU Master's Theses
Aging is associated with progressing cellular structural and functional changes, and sedentary behavior can exacerbate these hallmarks of aging. Routine exercise is known to have beneficial effects on physiological systems, but the exact molecular mechanisms behind the health benefits are unclear. Emerging evidence suggests extracellular vesicles called exosomes are involved in the intercommunication between cells and organs following exercise by delivering their cargo such as proteins and miRNAs. miRNA profiles in older adults following acute and chronic exercise need further exploration. Specifically, the effects of regular low-intensity physical activity (LPA) breaks in sedentary time on proteins and miRNA packaged in …
Mechanisms That Limit Oxidative Phosphorylation During High-Intensity Muscle Contractions In Vivo, Miles F. Bartlett
Mechanisms That Limit Oxidative Phosphorylation During High-Intensity Muscle Contractions In Vivo, Miles F. Bartlett
Doctoral Dissertations
Skeletal muscle oxidative capacity plays a critical role in human health and disease. Although current models of oxidative phosphorylation sufficiently describe skeletal muscle energetics during moderate-intensity contractions, much is still unknown about the mechanisms that control and limit oxidative phosphorylation during high-intensity contractions. In particular, the oxygen cost of force generation is augmented during exercise at workloads above the lactate threshold. Presently, it is unclear whether this augmentation in muscle oxygen consumption is driven by increased rates of oxidative ATP synthesis (ATPOX) or by decreases in the efficiency of ATPOX due to mitochondrial uncoupling. To address this …
Effects Of Life-Long Wheel Running Behavior On Plantar Flexor Contractile Properties, Alexander Nicholas Beechko
Effects Of Life-Long Wheel Running Behavior On Plantar Flexor Contractile Properties, Alexander Nicholas Beechko
Electronic Theses, Projects, and Dissertations
Aging in skeletal muscle is characterized by a loss in muscular performance. This is in part related to the direct loss of muscle mass due to senescence, known as sarcopenia. With age, skeletal muscles lose force production, contractile speed, and power production. The force velocity relationship of muscle is a product of force production and contraction speed, both of which decline with age; however, the mechanisms and trajectory of this decline are not well understood. Exercise has positive effects on muscle, and thus may assist in maintaining performance in old age. However, few long-term studies have been performed to examine …
Phase- Specific Changes In Rate Of Force Development And Muscle Morphology Throughout A Block Periodized Training Cycle In Weightlifters, Dylan G. Suarez, Satoshi Mizuguchi, William Guy Hornsby, Aaron J. Cunanan, Donald J. Marsh, Michael H. Stone
Phase- Specific Changes In Rate Of Force Development And Muscle Morphology Throughout A Block Periodized Training Cycle In Weightlifters, Dylan G. Suarez, Satoshi Mizuguchi, William Guy Hornsby, Aaron J. Cunanan, Donald J. Marsh, Michael H. Stone
ETSU Faculty Works
The purpose of this study was to investigate the kinetic and morphological adaptations that occur during distinct phases of a block periodized training cycle in weightlifters. Athlete monitoring data from nine experienced collegiate weightlifters was used. Isometric mid-thigh pull (IMTP) and ultrasonography (US) results were compared to examine the effects of three specific phases of a training cycle leading up to a competition. During the high volume strength-endurance phase (SE) small depressions in rate of force development (RFD) but statistically significant (p ≤ 0.05) increases in vastus lateralis cross-sectional area (CSA), and body mass (BM) were observed. The lower volume …
The Development Of Skeletal Muscle In Young Horses: An Ultrasonography And Satellite Cell Approach, Emma K. Lavigne
The Development Of Skeletal Muscle In Young Horses: An Ultrasonography And Satellite Cell Approach, Emma K. Lavigne
Honors Scholar Theses
Muscle growth in young horses is characterized by an increase in muscle cross-sectional area, which can be accomplished through the activation and differentiation of satellite cells. Satellite cells can be stimulated or inhibited in response to different cytokines and growth factors and are key mediators of muscle hypertrophy and regeneration. The aim of this study was to investigate the growth of the longissimus dorsi (LD) muscle in horses under 5 years of age and to obtain preliminary data on satellite cell behavior in foals. The area, width, height, and subcutaneous fat were measured using ultrasonography at 6-month increments over the …
A Comparison Of Three Computer-Based Methods Used To Determine Emg Signal Amplitude, Doug Renshaw*, Matthew R. Bice†, Camille Cassidy‡, James A. Eldridge‡, Douglas W. Powell‡
A Comparison Of Three Computer-Based Methods Used To Determine Emg Signal Amplitude, Doug Renshaw*, Matthew R. Bice†, Camille Cassidy‡, James A. Eldridge‡, Douglas W. Powell‡
James Eldridge
Electromyography is a commonly used method to determine relative effort and neuromuscular drive to skeletal muscle. A limitation of the interpretation of EMG within the literature is the many methods used to determine the intensity of muscle activation. In the current study, ten healthy young adults performed a level walking task while EMG was recorded from the tibialis anterior, medial gastrocnemius and fibularis longus. The EMG data were rectified and smoothed using the root mean squared (RMS). Peak RMS (pRMS), mean RMS (mRMS) and integrated EMG (iEMG) were normalized to the peak value within the subject and were used to …
Insulin Resistance And Muscle Insulin Receptor Substrate-1 Serine Hyperphosphorylation, Charles A. Stuart, Mary E. A. Howell, Brian M. Cartwright, Melanie P. Mccurry, Michelle L. Lee, Michael W. Ramsey, Michael H. Stone
Insulin Resistance And Muscle Insulin Receptor Substrate-1 Serine Hyperphosphorylation, Charles A. Stuart, Mary E. A. Howell, Brian M. Cartwright, Melanie P. Mccurry, Michelle L. Lee, Michael W. Ramsey, Michael H. Stone
ETSU Faculty Works
Insulin resistance in metabolic syndrome subjects is profound in spite of muscle insulin receptor and insulin-responsive glucose transporter (GLUT4) expression being nearly normal. Insulin receptor tyrosine kinase phosphorylation of insulin receptor substrate-1 (IRS-1) at Tyr896 is a necessary step in insulin stimulation of translocation of GLUT4 to the cell surface. Serine phosphorylation of IRS-1 by some kinases diminishes insulin action in mice. We evaluated the phosphorylation status of muscle IRS-1 in 33 subjects with the metabolic syndrome and seventeen lean controls. Each underwent euglycemic insulin clamps and a thigh muscle biopsy before and after 8 weeks of either strength or …
Twenty-One Days Of Lunar Environment Alters Muscle Fiber Areas In Mouse Gastrocnemius, Edwin M. Savio, Kevin L. Shimkus, Jeff M. Hord, John Will Deaver, Michael P. Wiggs, Brandon R. Macias, Florence Lima, Ramon D. Boudreaux, Yasaman Shirazi-Fard, Elizabeth S. Greene, Les A. Braby, Harry A. Hogan, John M. Lawler, Susan A. Bloomfield, James D. Fluckey
Twenty-One Days Of Lunar Environment Alters Muscle Fiber Areas In Mouse Gastrocnemius, Edwin M. Savio, Kevin L. Shimkus, Jeff M. Hord, John Will Deaver, Michael P. Wiggs, Brandon R. Macias, Florence Lima, Ramon D. Boudreaux, Yasaman Shirazi-Fard, Elizabeth S. Greene, Les A. Braby, Harry A. Hogan, John M. Lawler, Susan A. Bloomfield, James D. Fluckey
International Journal of Exercise Science: Conference Proceedings
Download PDF
The Effect Of Music As A Motivational Tool On Isokinetic Concentric Performance In College Aged Students, Maurice M. Godwin, Ronnette T. Hopson, Carley K. Newman, Timothy J. Leszczak
The Effect Of Music As A Motivational Tool On Isokinetic Concentric Performance In College Aged Students, Maurice M. Godwin, Ronnette T. Hopson, Carley K. Newman, Timothy J. Leszczak
International Journal of Exercise Science
International Journal of Exercise Science 7(1) : 54-61, 2014. Music has been identified as a motivational tool in physical activity and associated with improved performance in aerobic and anaerobic exercise. However, the effects of music on isokinetic strength testing have not been examined. The purpose of this study was to measure the difference in lower limb isokinetic force output in males and females when exposed to a motivational environment (arousing music) and non-motivational environment (silence). A 2 x 2 analysis of variance (group x gender) was used with participants (n = 19; 12 male, 7 female) serving as their …
Effects Of Multiple Bouts Of Long-Duration Hindlimb Unloading And Recovery On Rat Plantaris Muscle, Emily E. Jaroszewski, Kevin L. Shimkus, Yasaman Shirazi-Fard, Harry A. Hogan, James D. Fluckey
Effects Of Multiple Bouts Of Long-Duration Hindlimb Unloading And Recovery On Rat Plantaris Muscle, Emily E. Jaroszewski, Kevin L. Shimkus, Yasaman Shirazi-Fard, Harry A. Hogan, James D. Fluckey
International Journal of Exercise Science: Conference Proceedings
Exposure to microgravity results in a rapid reduction of muscle mass. However, few studies exist designed to examine the effects of multiple long-term exposures to microgravity with alternating recovery periods on skeletal muscle. To determine what happens to the recovery of skeletal muscle when faced with subsequent unloading and recovery periods. Male Sprague-Dawley (6 mo) were assigned to the following groups as shown in figure 1 below: 28d hindlimb unloading (1HU), 28d HU session followed by a 56d recovery bout of normal cage ambulation at 1g (1HU+REC), 2 cycles of 28d HU with a 56d recovery period between unloadings (2HU), …
Myogenin Modulates Exercise Endurance By Altering Skeletal Muscle Metabolism, James Eric Meadows
Myogenin Modulates Exercise Endurance By Altering Skeletal Muscle Metabolism, James Eric Meadows
Dissertations & Theses (Open Access)
The function of myogenic regulatory factors (MRFs) during adult life is not well understood. The requirement of one of these MRFs, myogenin (Myog), during embryonic muscle development suggests an equally important role in adult muscle. In this study, we have determined the function of myogenin during adult life using a conditional allele of Myog. In contrast to embryonic development, myogenin is not required for adult viability, and Myog-deleted mice exhibited no remarkable phenotypic changes during sedentary life. Remarkably, sedentary Myog-deleted mice demonstrated enhanced exercise endurance during involuntary treadmill running. Altered blood glucose and lactate levels in sedentary Myog-deleted mice after …
A Comparison Of Three Computer-Based Methods Used To Determine Emg Signal Amplitude, Doug Renshaw*, Matthew R. Bice†, Camille Cassidy‡, James A. Eldridge‡, Douglas W. Powell‡
A Comparison Of Three Computer-Based Methods Used To Determine Emg Signal Amplitude, Doug Renshaw*, Matthew R. Bice†, Camille Cassidy‡, James A. Eldridge‡, Douglas W. Powell‡
International Journal of Exercise Science
Electromyography is a commonly used method to determine relative effort and neuromuscular drive to skeletal muscle. A limitation of the interpretation of EMG within the literature is the many methods used to determine the intensity of muscle activation. In the current study, ten healthy young adults performed a level walking task while EMG was recorded from the tibialis anterior, medial gastrocnemius and fibularis longus. The EMG data were rectified and smoothed using the root mean squared (RMS). Peak RMS (pRMS), mean RMS (mRMS) and integrated EMG (iEMG) were normalized to the peak value within the subject and were used to …