Systems and Integrative Physiology Commons^™

Ultrasound-Derived Liver Composition And Metabolic Flexibility Under Exercise Stress, Rhodes Van Houten

All Master's Theses

Metabolic Associated Fatty Liver Disease (MAFLD) is characterized by abnormal liver fat accumulation in conjunction with metabolic syndromes. MAFLD affects 33% of individuals worldwide, though little is known about how increased liver fat impacts physiological responses to exercise. This study aimed to analyze the relationship between liver composition and metabolic flexibility during a graded exercise test.  Body composition was analyzed via dual-energy X-ray absorptiometry. Liver ultrasound was evaluated for echogenicity, where elevated mean gray volume (MGV) indicates abnormal liver tissue. Rates of fat (FATox) and carbohydrate (CHOox) oxidation (g/min), respiratory exchange ratio (RER), and blood lactate concentrations ([LA^-], …

An Exploratory Analysis Of The Role Of Sex In Load Carriage, Rachel E. Perez, Dustin R. Slivka, Brent C. Ruby

Graduate Student Theses, Dissertations, & Professional Papers

Axially loaded weight may impose a metabolic demand equivalent to that of fat mass (FM) during load carriage. Males (M) typically have a lower body fat percentage than females (F), resulting in metabolic demand differences during load carriage that may be mitigated by accounting for FM in pack loads. PURPOSE: To determine whether normalizing pack load to FM equalizes metabolic cost across sexes during load carriage. METHODS: Twenty-eight participants (14M, 23 ± 5 y, 1.81 ± 0.07 m, 78.7 ± 10.0 kg, 12.7 ± 5.4% body fat, VO₂peak 4.18 ± 0.54 L·min^-1; 14F, 22 ± 4 …

Molecular Mechanisms Of Exercise-Stimulated Resolution Of Inflammation And Its Dietary Dependence., Ernesto H. Pena Calderin

Electronic Theses and Dissertations

Diet-induced obesity and adipose tissue (AT) inflammation that ensues sets the stage for systemic metabolic inflammation, disrupted insulin signaling, and eventual type 2 diabetes (T2D) development. At the center of this pathology lies a disruption in endogenous inflammation resolution pathways characterized by an imbalance in lipid mediator production (greater abundance of pro-inflammatory to pro-resolving lipids). Additionally, obese states are characterized by adrenergic deficiency, especially in response to physical activity. Inflammatory processes have been experimentally mitigated by either the pharmacological inhibition of pro-inflammatory signals (i.e., Leukotriene B₄ (LTB₄) and its receptor BLT1, which establishes a potent chemotactic stimulus …

Regulation Of Skeletal Muscle Plasticity By The Gut Microbiome, Taylor R. Valentino

Theses and Dissertations--Physiology

Recent evidence suggests that the gut microbiome could play a role in skeletal muscle plasticity, providing novel treatments for muscle wasting diseases and/or performance enhancements. I first sought to determine if the gut microbiome is necessary for skeletal muscle adaptation to exercise. Forty-two, four-month old, female C57Bl/6J underwent nine weeks of weighted wheel running or remained in cage with a locked wheel, without or without the administration of antibiotics (treated). In response to wheel running, I found that antibiotic depletion of the microbiome led to a blunted hypertrophic response in the soleus muscle as measured by normalized muscle wet weight …

Effects Of Mindfulness And Stress Management On Neurocardiovascular And Psychological Outcomes, Aditi P. Vyas

Dissertations, Master's Theses and Master's Reports

There has been a higher prevalence of developing anxiety due to frequent episodes of stress among adults in recent years. Chronic anxiety can contribute to the prevalence of elevated blood pressure and hypertension. High anxiety and stress also contribute to overactivation of the sympathetic nervous system which can be quantified by increased muscle sympathetic nerve activity (MSNA). Sympathetic overactivation can lead to vasoconstriction and loss of arterial elasticity. Anxiety, MSNA, blood pressure, and arterial stiffness are all interconnected, thus studying these relationships is crucial to understand the underlying mechanisms for prevention and treatment of cardiovascular disease (CVD). Non-pharmacological and mind-body …

Relation Of Flt-1 And Endothelial Function In Women Soon After Delivery: Effect Of Physical Activity And Sedentary Behavior, Chloe W. Caudell

Senior Theses

Adverse pregnancy outcomes (APOs) are believed to be caused by poor placental formation. APOs can be characterized by elevated levels of a circulating Fms-like tyrosine kinase biomarker called Flt-1, produced by the placenta when its blood vessels are shallow or inadequately formed. Flt-1 acts directly on the maternal endothelium to impair vascular function during pregnancy and contributes to maternal features of APOs. This study aimed to evaluate the relation of Flt-1 and endothelial function in women soon after delivery. This study also aimed to evaluate the relation of Flt-1 and physical activity and sedentary behavior in women during and soon …

To Flex Or Rest: Does Adding No-Load Isometric Actions To The Inter-Set Rest Period In Resistance Training Enhance Muscular Adaptations? A Randomized-Controlled Trial, Brad J. Schoenfeld, Jozo Grgic, Bret Contreras, Kenneth Delcastillo, Andrew Alto, Cody Haun, Eduardo O. De Souza, Andrew D. Vigotsky

Publications and Research

We aimed to investigate the effects of resistance training (RT) combined with no-load isometric actions (iso-holds) during the inter-set recovery period versus RT that involves passive inter-set rest on muscular strength, muscular hypertrophy, and muscular endurance in resistance-trained men. Twenty-seven resistance-trained male volunteers were randomly assigned to either a traditional group (TRAD) that performed a hypertrophy-oriented RT routine with the rest intervals spent passively (n = 13) or to a group that supplemented traditional RT with iso-holds (ISO) for the working muscle group between each set (n = 14). Training for both routines consisted of three weekly sessions performed for …

Metabolic And Cardiovascular Marker Alterations During Critical Training In Wildland Firefighters, Shae Gurney

Graduate Student Theses, Dissertations, & Professional Papers

Introduction: Wildland firefighters (WLFFs) are confronted with numerous physical and mental stressors. Pre-fire season includes an intense 2-week critical training (CT) period; a preparatory phase of multiple activities that can result in injury, illness, and rhabdomyolysis. The purpose of this study was to identify physiologic changes in metabolic, inflammatory, and oxidative stress biomarkers during 2 weeks of CT in WLFFs.

Methods: Eighteen male (29.4 ± 1.1 yr, 182.1 ± 1.6 cm) and three female (26.7  2.6 yr, 169.5  4.2 cm) participants were recruited from a Type I interagency hotshot crew and monitored over their 2-week CT. Fitness was …

Muscle Soreness And Damage During Wildland Firefighter Critical Training, Katherine Sue Christison

Graduate Student Theses, Dissertations, & Professional Papers

Introduction: Wildland firefighters (WLFF) undergo a critical training (CT) period immediately before the firefighting season. The intensity of CT exercise could lead to muscle damage, as previously reported cases of rhabdomyolysis in WLFFs have been documented. This study established the effects of activities performed during a two-week CT period on acute markers of muscle damage in WLFFs.

Methods: 18 male and 3 female Type I Interagency Hotshot WLFFs were studied during a 14-day critical training period. Upper- (US) and lower-body (LS) muscle soreness and daily body weight (BW) scales were collected. Venous blood was collected on Days 1, 4, 8, …

Acute Physiological Responses To Arm-Cranking With Blood Flow Restriction, Benjamin Cockfield

Dissertations, Master's Theses and Master's Reports

Physiological responses to aerobic blood flow restriction exercise (BFR) are well documented for lower-body exercise but not upper-body exercise. I evaluated cardiorespiratory (heart rate, VO2, RER, ventilation), metabolic (tissue saturation, deoxyhemoglobin concentrations), and perceptual (effort, pain) responses to arm cranking with BFR at varying arterial occlusion pressures (AOP). Ten adults performed 4 intermittent arm cranking protocols (6x2-min, 1-min recovery): 1) low load (LL) – 40%VO2peak and 0% AOP; high load (HL) – 80%VO2peak and 0% AOP; (BFR50) – 40%VO2peak with 50% AOP; (BFR70) – 40%VO2peak with 70% AOP. Heart rate, RER, and ventilation, were higher with BFR compared to LL …

Similar Muscular Adaptations In Resistance Training Performed Two Versus Three Days Per Week, Thiago Lasevicius, Brad Jon Schoenfeld, Jozo Grgic, Gilberto Laurentino, Lucas Duarte Tavares, Valmor Tricoli

Publications and Research

The purpose of the present study was to compare changes in muscle strength and hypertrophy between volume-equated resistance training (RT) performed 2 versus 3 times per week in trained men. Thirty-six resistance-trained men were randomly assigned to one of the two experimental groups: a split-body training routine (SPLIT) with muscle groups trained twice per week (n = 18) over four weekly sessions, or a total-body routine (TOTAL), with muscle groups being trained three times per week (n = 18) over three weekly sessions. The training intervention lasted 10 weeks. Testing was carried out pre- and post-study to assess maximal muscular …

Total Energy Intake And Self-Selected Macronutrient Distribution During Wildland Fire Suppression, Alexander N. Marks, Joseph A. Sol, Joseph W. Domitrovich, Molly R. West, Brent C. Ruby

Graduate Student Theses, Dissertations, & Professional Papers

Introduction: Wildland firefighters (WLFF) work long hours in extreme environments resulting in high daily total energy expenditure (TEE). Increasing work shift eating episodes and/or providing rations that promote convenient feeding has shown augmented self-selected work output, as has regular carbohydrate (CHO) consumption. It remains unclear how current WLFF feeding strategies compare to more frequent nutrient delivery. Our study’s aim was to determine WLFFs’ self-selected field total energy intake (TEI), composition, and patterns feeding during wildland fire suppression shifts.

Methods: 86 WLFF (16 female, 70 male; 27.5 ± 6.4 yr) deployed to fire incidents across the United States throughout the 2018 …

Thermoregulatory Dysfunction In Multiple Sclerosis, Dustin R. Allen

Applied Physiology and Wellness Theses and Dissertations

Multiple sclerosis (MS) is a progressive neurological disease of the central nervous system (CNS) affecting an estimated 2.3 million people worldwide. Marked by lesions in the brain and spinal cord, MS leads to conduction abnormalities in the CNS. Evidence suggests ~60% of individuals with MS experience temporary worsening of their symptoms upon exposure to heat. Adding complexity, observational evidence suggests these individuals exhibit reduced thermoregulatory responses in upon increases in core temperature. Consequently, these individuals face a vicious cycle of heat sensitivity and thermoregulatory dysfunction, substantially impacting their quality of life. With this in mind, our lab is dedicated to …

Cancer Cachexia: Metabolic Changes That Occur In Oxidative Capacity And Carbohydrate And Lipid Metabolism Of The Liver, Sarah Ramey

Health, Human Performance and Recreation Undergraduate Honors Theses

BACKGROUND: Cancer cachexia is defined as cancer-associated muscle wasting, and is a cancer side effect that dramatically affects cancer prognosis, is thought to be at least partially mediated by increased energy expenditure, and is directly responsible for the death of 20-40% of all cancer patients. Although the liver is known to be a predominant regulator of whole body metabolism, there is little known about its relationship to the development of cancer cachexia. PURPOSE: The purpose of this exploratory study was to investigate alterations in liver metabolism by examining measures of hepatic glycogen storage, oxidative phenotype and lipid content throughout the …

Thermoregulatory Adaptations Following Sprint Interval Training, Jonathan E. Wingo, Charlie P. Katica, Svetlana Nepocatych, Andrew T. Del Pozzi, Greg A. Ryan

Journal of Human Performance in Extreme Environments

Traditional endurance training typically involves weeks of long-duration (60–90 min) exercise performed at a moderate to vigorous intensity. An alternative paradigm, sprint interval training, is characterized by multiple bouts of short-duration, high-intensity exercise. Similar fitness benefits from the two paradigms have been demonstrated, but whether sprint interval training—like traditional endurance training—induces heat acclimation remains unclear.

Purpose

To test the hypothesis that sprint interval training performed over six sessions results in measureable thermoregulatory and cardiovascular adaptations consistent with heat acclimation.

Methods

Seven untrained men [mean ± SD, 13 ± 5% body fat, 22 ± 3 y, 3.1 ± 0.3 L/min peak …

Can A Comprehensive Transition Plan To Barefoot Running Be The Solution To The Injury Epidemic In American Endurance Runners?, Michael A. Scarlett

CMC Senior Theses

Fossils belonging to the genus Homo, dating as far back as two million years ago, exhibit uniquely efficient features suggesting that early humans had evolved to become exceptional endurance runners. Although they did not have the cushion or stability-control features provided in our modern day running shoes, our early human ancestors experienced far less of the running-related injuries we experience today. The injury rate has been estimated as high as 90% annually for Americans training for a marathon and as high as 79% annually for all American endurance runners. There is an injury epidemic in conventionally shod populations that …

Outline Plan For A Student-Involved Fitness Assessment Program At Western Michigan University, Joanna Gangwisch

Honors Theses

This research was aimed at developing a fitness assessment program that would provide undergraduate exercise science students at Western Michigan University (WMU) with hands on experience that would successfully prepare them for their internships and future careers as well as benefiting the campus community at large. Data for this research was obtained by examining the student recreation center websites and sending out an email/phone questionnaire to WMU’s 10 peer institutions. Direct comparisons were made and evaluated. On the basis of the results of this research, it can be concluded that WMU’s exercise science department and student recreation center together could …

A Movement Tool Kit For The Divergent And Convergent Cps Guidelines: Instruction Cards And Activity Floor Mats, Adela Vangelisti

Creativity and Change Leadership Graduate Student Master's Projects

A Movement Tool Kit for the Divergent and Convergent CPS Guidelines:

Instruction Cards and Activity Floor Mats

Movement is as natural to humans as breathing is, and, yet, passivity starts early in schools. We are taught to sit still and in silence for long periods of time. By the time we reach adulthood and enter the workforce, we have almost forgotten our sense of embodiment. This lack of movement is counter-productive, not only to learning but to the development of creativity as well. For this project, I designed a tool to recapture the joy and playfulness of movement. Furthermore, the …

A Comparison Of Fatigue During Cardiocerebral Resuscitation With Different Compression Rates Among Layperson And Professional Rescuers, Christopher Cassidy

Master's Theses

Quality chest compressions during Cardiopulmonary Resuscitation (CPR) are vital to maintaining adequate perfusion of oxygenated blood to the organs of the body to sustain life. Over the years, the compression rate recommended in Basic Life Support (BLS)/ Advanced Cardiac Life Support (ACLS) protocols for the best possible outcome has risen, and with that increase there are questions regarding rescuer fatigue and the effectiveness of compressions. Layperson and professional rescuers, answering to an emergency, both maintain continuous chest compressions until advanced life support arrives. Depending on the location, this arrival time would most likely be longer than the two minute standard …

Digital And Clinical Refractometers Are Valid Instruments For The Measure Of Hydration Status, A. J. Niemann, S. W. Yeargin, L. E. Eberman, H. M. Mata, H. A. Adams, D. J. Dziedzicki

Symposium 2012

Although some instruments have been validated for clinical measure of hydration status, new and currently invalid instruments are available for purchase and clinical use. Athletic trainers commonly use these instruments to assess hydration status for weight checks and body mass loss charts due to their ease of use. However, the validity of these popular instruments has not yet been established.