Systems and Integrative Physiology Commons^™

The Effect Of Breathing Patterns Common To Competitive Swimming On Gas Exchange And Muscle Deoxygenation During Heavy-Intensity Fartlek Exercise, Kevin J. Grossman

Electronic Thesis and Dissertation Repository

The purpose of this study was to compare the respiratory and muscle deoxygenation (HHb) responses of regulated breathing versus free-breathing, during continuous exercise (CONLD) and intermittent 5s breath holds (BH) (CONLD-BH), intermittent 5s sprint (FLK) and combined 5s BH and sprint (FLK-BH) followed by 25s of free-breathing. Oxygen uptake(V̇O₂)was unchanged between CONLD (2.12±0.35L/min) and CONLD-BH (2.15±0.42L/min; p=0.116), and FLK (2.24±0.40L/min) and FLK-BH (2.20±0.45L/min; p=0.861). Δ[Hb_tot]: CONLD (3.3±1.6µM) > CONLD-BH (-2.5±1.2µM; ∆177%; p<0.001), but unchanged between FLK (2.0±1.6µM) and FLK-BH (0.82±1.4µM; p=0.979). Δ[HHb]: CONLD (7.3±1.8µM) > CONLD-BH (7.0±2.0µM; ∆4%; p=0.011), and FLK (6.7±1.8µM) < FLK-BH (8.7±2.4µM; p<0.001). It is suggested that the unchanged V̇O₂ between CONLD and CONLD-BH was supported by increased deoxygenation, reflected by decreased ∆[Hb_tot] and blunted …

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 …

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 …

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 …

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 …

The Neuroprotective Effects Of Endurance Training On The Aging Brain, Katelyn Norton

Electronic Thesis and Dissertation Repository

Dysregulation of autonomic control often develops with advancing age, favoring a chronic state of heightened sympathetic outflow with parasympathetic withdrawal. However, the mechanisms of this age-related autonomic impairment are not known and may relate to alterations in brain structure (e.g. cortical atrophy) and/or altered neural function, particularly in regions related to the cortical autonomic network, namely, the medial prefrontal cortex (MPFC), insula cortex (IC), and hippocampus (HC). Exercise exerts beneficial effects on brain structure and, in the case of cognition, neurologic function; however, how exercise affects regions of the brain related to autonomic function are not known. This thesis tested …

Lifestyle Contributors To Cardiovascular Disease Risk, Adam J. Berrones

Theses and Dissertations--Kinesiology and Health Promotion

Aortic stiffness is an independent risk factor that has prognostic value regarding future cardiovascular disease (CVD) events such as myocardial infarction, strokes, and heart failure. Although death rates due to coronary heart disease have declined in recent years, the leading global killer remains CVD and prevalence is still high. Understanding lifestyle contributors associated with aortic stiffness would provide the public with insight into targeting key health-related behaviors.

The purpose of this observational study was to examine the association of physical activity, physical function, and dietary quality as independent factors contributing to aortic stiffness in apparently healthy middle aged men. Fifty-two …

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 …

Role Of Adenylyl Cyclase S674 In Central And Forearm Vasomotor Control, James Corkal

Electronic Thesis and Dissertation Repository

This study examined the cardiac and vasomotor responses to submaximal handgrip exercise and beta-adrenergic control in carriers (n = 6) and non-carriers (n = 4) of a genetic variant of adenylyl cyclase 6 (AC S674). Rhythmic handgrip contractions (1 minute bout; 2 second contraction-relaxation period) were performed at three different intensities (20, 40, and 60% of maximal voluntary contraction force) to test the vasodilatory response to exercise. Additionally, two 5 minute infusions of isoproterenol (0.01 and 0.02 µg·kg^-1·min^-1 diluted in 5% dextrose) and one 10 minute infusion of propranolol (0.1 mg·kg^-1 diluted in 0.9% saline) were …

Neuromuscular Function Following Lengthening Contractions, Geoffrey A. Power

Electronic Thesis and Dissertation Repository

Unaccustomed lengthening contractions have been shown to impair muscle function - however little is known regarding this impairment on muscle power - specifically, the velocity component of power during voluntary contractions in humans. The four studies presented in my thesis investigated power-loss following lengthening contractions in healthy young and old women and young men.

The purpose of Study 1 was to determine reliability of velocity-dependent power of the dorsiflexors using the isotonic mode of the Biodex Dynamometer. I determined the isotonic mode is reliable and can be used to track changes in velocity and power following fatigue and lengthening contractions. …

Neuroprotective Effects Of Long-Term Endurance Training On The Cortical Autonomic Network In The Aging Brain, Torri A. Luchyshyn

Electronic Thesis and Dissertation Repository

This study tested whether long-term endurance training in older adults (ET; n = 15, 55 ± 4 years, relative VO₂max = 50 ± 8 ml/kg/min) would alter cardiovagal control and preserve the cortical autonomic network compared to age-matched controls (CON; n = 15, 56 ± 4 years, relative VO₂max = 37 ± 9 ml/kg/min). The hypothesis predicts 1) altered deactivation patterns of the ventral medial prefrontal cortex (vMPFC) in response to isometric hand grip (IHG) and 2) greater indices of cardiovagal control; a) increased baroreflex sensitivity at rest, b) greater heart rate change (ΔHR) and c) …