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Stretch Activation During Fatigue Improves Relative Force Production In Fast-Contracting Mouse Skeletal Muscle Fibers, Philip C. Woods

Masters Theses

Stretch activation (F_SA) is the delayed increase in fiber specific tension (force per cross-sectional area) following a rapid stretch and can improve muscle performance during repetitive cyclical contractions. Historically considered minimal in skeletal muscle, our recent work showed the ratio ofstretch- to calcium-activated specific tension (F_SA/F₀) increased from 10 to 40% with greater inorganic phosphate (Pi) levels in soleus muscle fibers (Straight et al., 2019). Given Pi increases with muscle fatigue, we hypothesize that F_SA helps maintain force generation during fatigue. To test this, F_SA, induced by a stretch of 0.5% …

An Examination Of Inter-Limb Functional Asymmetry After A Fatiguing Bout Of Exercise In High Level Soccer Players, Nestor Urrea

Theses and Dissertations

INTRODUCTION: Inter-limb functional asymmetries greater than 15% have been linked to a greater incidence of injury. Moreover, asymmetries greater than 10% have shown greater risk of injury and worsened sport performance, especially for strength and power capabilities, in athletes of multiple sports. Fatigue and sex are factors that seem to influence injury rates as well as greater asymmetries between limbs. This research project aims to investigate the effects of a fatiguing bout of exercise in strength and power inter-limb functional asymmetries in male and female soccer players. It was hypothesized that strength and power asymmetries are negatively affected after a …

Factors Influencing Hard Running Distances In Ncaa Division I Female Soccer Players, Isaac A. Sam

Dissertations and Theses

As the total distances covered in soccer games have remained relatively constant, the hard running distances covered by players have shown varying changes due to the higher physical demands and dynamics of team running performances. Although factors affecting the total distances covered in a match are multifactorial, no study has specifically examined match performance indicators (MPI) that impact hard running distances (HRD). Consequently, the purpose of this study was to better understand how MPI (hard running efforts, turnovers, minutes played, duels won, duels lost, and pass completions) are associated with HRDs and to investigate how each variable contributes to HRDs …

Assessing Structural And Functional Brain Alterations And Work-Related Fatigue In Non-Hyposmic And Hyposmic Covid-19 Survivors, Rakibul Hafiz

Dissertations

In the year 2019, life began to change at the advent of a global pandemic caused by the novel coronavirus. Mask mandates and mass vaccinations have mitigated the effects significantly, yet cases keep rising with new variants, especially, in densely populated countries, like India. Recent neuroimaging evidence shows the virus can attack the central nervous system (CNS). However, exactly which brain regions undergo structural and functional changes remain largely unknown. Many patients experience 'loss of/reduced sense of smell' (i.e., hyposmic) and an alarming number of survivors develop persistent symptoms ('long-COVID') for several months after initial infection. Fatigue is the most …

Effects Of Acute Exercise Intensity On Memory: Considerations Of Timing And Aerobic Endurance, William Meyers, Caroline Loeb, Mary Collins West, Bailey Bass

Honors Theses

The primary objective of this study was to find the optimal acute exercise intensity and post-exercise recovery time to enhance memory retention. A secondary objective of study was to evaluate the influence of aerobic endurance on memory and whether endurance capacity interacts with exercise intensity and post-exercise recovery period to influence memory performance. Participants were 54 undergraduate and graduate students at the University of Mississippi, with an age range of 18-23 years. Participants completed 13 visits in total. The first visit evaluated their aerobic endurance, with the remaining 12 visits including a 3 (Intensity: Control, Moderate, Vigorous) by 4 (Post-Exercise …

Exploration Of Warm-Up Protocols On Muscular Fatigue, Sahil Kapadia

Honors Undergraduate Theses

Muscular dystrophy is a genetically linked myopathy with no cure available. The lack of a cure makes early detection and treatment of muscular dystrophy imperative. When reviewing protocols examining muscular fatigue at submaximal isometric contractions, proper warm-up appeared to be absent and could have caused skewed results and conclusions. This study examines the effects of implementing a warm-up protocol before fatiguing trials. In this study, 10 adult subjects conducted fatiguing protocols with the right rectus at submaximal isometric contractions. The warm-up period included a light walk along with contractions at 20% and 33% of maximal voluntary isometric contraction (MVIC) levels. …

The Effects Of Fatigue On Landing Impact Forces And Postural Steadiness In Collegiate Volleyball Players, Zebadiah P. Boos

Graduate Student Theses, Dissertations, & Professional Papers

Background: The onset of exhaustion can reduce the performance of an athlete and may add to the risk of injury. This establishes the necessity to understand when and how the athlete’s performance is altered as they become fatigued in competition or practice. The aim of this study was to determine the effects of fatigue on dynamic and static tasks in collegiate volleyball athletes by implementing a fatiguing jump protocol. Methods: To replicate an in-game or in-practice situation, five sets of 30 countermovement jumps (CMJ) at 85% maximal height was implemented. Prior to the fatigue protocol, a baseline measure of CMJ …

The Effect Of Fatigue On Lower Extremity Electromyography During Clean Performance In Elite Female Weightlifters, John A. Littner

Graduate Research Theses & Dissertations

The clean is a primary movement in the sport of Olympic weightlifting. Management of fatigue is essential to optimizing weightlifting performance. The purpose of this study was to examine the effects of fatigue on EMG activation during clean performance in elite female weightlifters. Electromyography (EMG) data was collected bilaterally from the vastus lateralis (VM) and vastus lateralis (VL) during maximum voluntary isometric contraction (MVIC) and clean trials. Muscle activity was collected during pre- and post-fatigue clean trials at 60%, 70%, and 80% of the subject’s self-reported one repetition maximum (1RM). Subjects completed a fatiguing protocol consisting of two sets of …

Comparison Of The Times To Exhaustion, Physiological, Perceptual, And Neuromusuclar Responses During Constant Heart Rate, Constant Vo2, And Constant Power Exercise, Pasquale Jiovanni Succi

Theses and Dissertations--Kinesiology and Health Promotion

The purposes of this study were to: 1) Determine if there are differences in the sustainability of exercise when anchored at critical heart rate (CHR), the VO₂ associated with CHR (VO₂CHR), or the power output associated with CHR (PCHR); 2) examine the patterns of responses in power output, metabolic (heart rate [HR], VO₂, respiration rate [RR]), neuromuscular (electromyographic [EMG] amplitude [AMP], mean power frequency [MPF], mechanomyographic [MMG] AMP and MPF, perceptual (rating of perceived exertion [RPE]), and muscle oxygenation responses (%SmO₂) during exercise anchored by HR, VO₂, and power output; and …

Mechanisms And Therapeutic Interventions For Breast Cancer-Induced Fatigue And Mitochondrial Dysfunction, David Andrew Stanton

Graduate Theses, Dissertations, and Problem Reports

According to the latest statistics from the National Cancer Institute (NCI), about 1 in 8 U.S. women (~13%) will develop invasive breast cancer over the course of their lifetime. This translates to an estimated 268,600 new cases of breast cancer for the year 2019, and these diagnoses will collectively make up 15% of all new cancer cases across all cancer types. The majority of these women will experience the often-debilitating symptom of breast cancer-induced fatigue. these patients often have difficulty performing normal activities of daily living, have decreased tolerance to traditional tumor-directed therapies, and have higher rates of cancer recurrence. …

Long-Term Disability Following A Hamstring Injury, Savannah Mclain

Electronic Theses and Dissertations

PURPOSE: Injuries to the hamstring complex are one of the most commonly seen lower extremity injuries in athletic populations. It is currently unknown how psychological or sociological factors affect an athlete after the recovery process has ended and if these factors play a role in re-injury rates relating to the hamstring. It is also unknown if athlete confidence level changes while in a fatigued state after an athlete returns to play from a hamstring injury. METHODS: Twenty-six physically active adults with and without a previous hamstring injury were recruited for this study. Participants completed a Qualtrics survey that …

Examination Of Sex- And Limb-Specific Fatigue During Unilateral, Isometric Forearm Exercise, Caleb Christian Voskuil

Theses and Dissertations--Kinesiology and Health Promotion

The purpose of this study was to examine the effects of unilateral, isometric handgrip holds to failure for the dominant (Dm) and non-dominant (NDm) limb on ipsilateral ([IPS] exercised side) and contralateral ([CON] non-exercised side) performance fatigability. Twenty individuals participated in this study (Men [n =10]; Women [n = 10; Composite Demographics: Age: 22.2 years; Height: 174.4 cm; Body Mass: 75.0 kg) and completed three visits. Two, 6 s maximal voluntary isometric contractions (MVICs) for the Dm and NDm limb were performed during visit 1, followed by a familiarization of the fatigue test. Visits 2 and 3 included an isometric, …

The Acute Effect Of High Intensity Resistance Training On Subsequent Firefighter Performance, Mark Ryan Mason

Theses and Dissertations--Kinesiology and Health Promotion

High intensity resistance training (HIRT) is commonly performed by structural firefighters to enhance preparedness for occupational demands. Despite the potential for HIRT to induce beneficial adaptations over time, it is important to determine if a single on-duty HIRT session is detrimental to subsequent occupational physical ability due to exercise-induced fatigue. Therefore, the primary purpose of this study was to assess the acute effect of HIRT on occupational physical ability in structural firefighters and to determine the time course of recovery. The secondary purpose was to determine if timed completion of a standardized bout of HIRT was correlated to occupational performance …

Breast Cancer Associated Muscle Fatigue: Novel Targets To Improve Survival And Quality Of Life, Hannah Elizabeth Wilson

Graduate Theses, Dissertations, and Problem Reports

Women diagnosed with breast cancer (BC) currently represent the largest group of cancer survivors in the United States, accounting for over 20% of those living after a cancer diagnosis. Most BC survivors report an unusual degree of fatigue, which can present prior to diagnosis and continue for many years after treatment cessation. Recent studies show that deficits in muscle function predict shorter survival in cancer, perhaps due to the fact that fatigue is known to reduce a patient’s tolerance to anti-cancer therapies. Therefore, improving muscle function in BC patients has the potential to improve both quality of life and survival …

Identifying Metabolites As Markers Of Fatigue In Athletes, Christopher D. George

Honors Theses

Fatigue in athletes caused by inadequate rest and other stressors can be severely detrimental to their health, and yet there is no reliable way to measure and track fatigue. Many classical measures of fatigue like body mass and resting heart rate are not reliable ways to track the physical fatigue of an athlete because they can change with many factors. In addition, it is not known how academic stress on top of physical stress affects fatigue. Metabolomics is a relatively new area of study and tracking metabolites offers the possibility to produce biomarkers to assess fatigue. This study collected saliva …

Neuromuscular Responses At Acute Altitude Exposure During Fatiguing Dynamic Exercise Of The Biceps Brachii, Jasmin Renee Jenkins

Open Access Theses & Dissertations

BACKGROUND: The capacity to do work is greatly affected by high altitude exposure. Larger muscle groups of the lower body and exercises primarily aerobic in nature have been well investigated at high altitude. The present study examined acute altitude exposure on the number of repetitions to failure and electromyographic (EMG) repetition duration (Time), EMG root mean square (RMS) and EMG mean power frequency (MPF) during dynamic constant external resistance (DCER) exercise of the biceps brachii.

METHODS: Thirteen subjects performed two sets of fatiguing DCER arm curl repetitions to failure at 70% of their one repetition maximum (1RM) obtained at 1067 …

Anaerobic Capacity Measures In Healthy Active Adults Ages 18-29: Normative Reference Values And Differences Between Sex, Dylan E. Roberts

Cal Poly Humboldt theses and projects

The purpose of this study was to develop normative reference values for the modified Anaerobic Speed Test (mAST), an anaerobic capacity test that can be administered and completed on a commercial treadmill. The mAST of 15% grade has been created as one of the only protocols based on the original AST protocol of 20% grade. However, no percentile norms currently exist for this protocol, limiting its usefulness and interpretation of results. This paper presents normative values for active healthy adults ages 18-29, separated by sex. The sample consisted of 276 active healthy volunteers (161 men and 115 women). All mASTs …

The Training Of A Para Powerlifter: A Case Study Of Adaptive Monitoring, Training And Overcoming, Derek Wilcox

Electronic Theses and Dissertations

Paralympic athletes (PA) appear to be more prone to chronic overuse injuries from daily wheelchair or crutch use. Over half of these injuries are shoulder related which can deleteriously impact quality of life. Adaptive powerlifters (AP) are a subdivision of Paralympic athletes and are at a higher risk for catastrophic injuries as compared to their counterparts, due to the compound of fatigue and lifting of maximal weights. For this reason, it is vital to have well-designed training plans for these athletes in order to preserve quality of life and maximize performance in competition. Unfortunately, there is a lack of literature …

Tropomyosin-Based Effects Of Acidosis On Thin-Filament Regulation During Muscle Fatigue, Brent Scott

Masters Theses

Skeletal muscle fatigue is defined as a loss in the force/velocity generating capacity of a muscle. A portion of the loss in function is attributable to effects of acidosis (i.e. low pH) on the regulatory proteins, troponin and tropomyosin (Tm), which regulate the binding of myosin and actin in a calcium (Ca⁺⁺) dependent manner. However, the relative role of troponin and Tm on myosin-actin function during acidosis is not clear, nor are the mechanisms underlying these effects. PURPOSE: To determine the role of Tm in the acidosis-induced depression of muscle function using isolated muscle proteins in an in …

The Regulation Of Skeletal Muscle Fatigue During The Progression Of Cancer Cachexia, Brandon N. Vanderveen

Theses and Dissertations

Cachexia is the unintentional loss of body weight secondary to chronic disease and is prevalent is roughly 50% of cancer patients. The loss of body weight and skeletal muscle mass is reduced functional capacity associated with reduced life quality. The etiology of cachexia is multimodal and complex; however, cachexia has been linked to several systemic (e.g. chronic inflammation, hypogonadism, anemia, insulin resistance) and behavioral (e.g. anorexia, inactivity) changes that can compound to accelerate muscle mass and body weight loss. While several inflammatory cytokines are associated with cachexia’s disease progression, our laboratory has established that Interleukin-6 (IL-6) is a key regulator …

The Role Of Sirt1 In Skeletal Muscle Function And Repair Of Older Mice, Matthew John Myers

Graduate Theses, Dissertations, and Problem Reports

Human skeletal muscle is a highly metabolic tissue necessary for mobility and coordination. Responsible for approximately one-fifth of the resting human metabolism, skeletal muscle is also an important regulator of metabolites like glucose and contributes to the regulation of body temperature. Although there is a gradual decline in muscle mass associated with aging, a certain percentage of the population suffer from severe muscle mass and strength deterioration, classified as sarcopenia (5-13% for people aged 60-70 years old, 11-50% for those 80 or older). Sarcopenia is linked to increased morbidity and mortality rates in the elderly population, while annual healthcare costs …

Spinal Motor Neuron Excitability During Fatigue, Nathalie Cecire

Theses and Dissertations (Comprehensive)

Fatigue during sustained or repeated muscular contractions can be from contractile failure within the muscle or reduced excitability in the supraspinal and spinal motor neurons. However, spinal motor neurons can also compensate for fatigue. We speculate that one way the spinal motor neuron compensates for fatigue is through an increase in excitability via the activation of persistent inward currents (PIC). In other conditions where there is a reduction in descending drive, such as during spinal cord injury and aging, there are adaptions of the spinal motor neurons to have elevated PIC amplitudes or towards a greater prevalence of PIC, respectively. …

The Task At Hand: Fatigue-Associated Changes To Corticospinal Excitability During Writing, Kezia Cinelli

Theses and Dissertations (Comprehensive)

Corticospinal excitability as measured via transcranial magnetic stimulation (TMS) is highly dependent on the task being performed at the time of stimulation. As such, this study sought out to measure corticospinal excitability during the relevant, daily task of writing and compare it to the conventional abduction task often utilized. We used single-pulse motor evoked potentials (MEPs) to provide a measure of corticospinal excitability and cortical silent period (CSP) duration, and paired-pulse conditioned MEPs to assess short-interval intracortical inhibition (SICI) and intracortical facilitation (ICF) recorded from the right first dorsal interosseous (FDI) of 19 participants on two randomized and counter-balanced days. …

An Investigation Into Fatigue Management: Effects Of Two Different Loading Protocols On Markers Of Inflammation And The Endocrine Response, Jake Bernards

Electronic Theses and Dissertations

The purposes of this dissertation were to 1) determine the effectiveness of the neutrophillymphocyte ratio (NLR) as an athlete monitoring tool in resistance training and 2) determine if repetition maximum or relative intensity loading scheme is superior in managing fatigue through the hormonal, inflammatory, and performances response throughout a 10-week periodized resistance training program. Results from the dissertation give merit to continued research regarding the use of NLR as a monitoring tool to help determine the degree of recovery. Furthermore, results from this dissertation lead to questioning the effectiveness of using a repetition maximum (RM) loading scheme within a periodized …

Impact Of An Exercise Program On Stress, Fatigue, And Quality Of Life For Individuals Living With Primary Immunodeficiency Disease, Kerri Sowers

Department of Physical Therapy Student Theses, Dissertations and Capstones

Background: There are over 300 Primary Immunodeficiency diseases (PID) that are a result of a genetic or idiopathic dysfunction of any aspect of the immune system. These conditions result in a higher frequency of infections, autoimmune conditions, or malignancies. Moderate intensity exercise is thought to help the immune system, while high intensity exercise may have a negative impact on immune function. The impact of exercise on individuals with an impaired immune system due to PID is not yet understood. Purpose: The purpose of this study was to investigate whether a low to moderate intensity exercise program would have an effect …

Quantifying Changes In Accelerations And Heart Rate Indicative Of Fatigue During Condensed Competitions In Elite Youth Ice Hockey Players, Kenneth L. Martel

Master's Theses and Doctoral Dissertations

Thirty-three elite youth ice hockey players wore Bioharness-3 (Zephyr, MD) sensors to compare accelerations (ACC) and heart rate (HR) over four games (G1–G4) in three days, in order to establish changes in cardiovascular stress and physical exertion associated with fatigue. Peak ACC and HR across multiple time frames were quantified and analyzed in conjunction to determine exertion profiles for each game. MANOVAs for peak ACC and HR, at each time point across G1–G4 and multiple games per day (M1, M2) for magnitude and time as main effects were performed. HR beats per minute decreased between G1 and G3/G4 in time …

The Effects Of Flexor Pronator Mass Fatigue On Medial Elbow Stability, Nathaniel Harvey Millard

Theses, Dissertations and Capstones

Introduction: The medial elbow is supported from valgus loading with the ulnar collateral ligament (UCL), the flexor pronator mass (FPM), and the radial head. Fatigue of muscle can lead to a decrease in force production. The decrease in force production can lead to a decrease in joint stability. This study tested the effect of fatigue of the FPM muscles on the width of the medial joint space.

Methods: Thirty-one participants volunteered for this study (18 female and 12 male, 1 excluded; mean height 170.2±10.1 cm, mean weight 71.2±15.6 kg, mean age 21.53±1.87 years old). Ultrasound images of the width of …

Wheelchair Fatigue Reducer, Aaron Miller, Dennis Andre Norfleet

Chancellor’s Honors Program Projects

No abstract provided.

Relationship Between Metabolic By-Products And Nervous System Failure/Fatigue, Tyler Mitchell Farney

LSU Doctoral Dissertations

Fatigue has generally been defined as an acute impairment of exercise/sport performance that includes both an increase in the perceived effort necessary to exert a desired force or power output, and the inability to produce the desired force or power output. The majority of research to date looking at fatigue has focused upon substrate utilization, however, what is relatively unknown is the contribution the nervous system has upon fatigue. Therefore, the purpose of this dissertation was to investigate potential mechanisms that relate to neural fatigue. An additional purpose was to determine if there were any relationships between metabolic by-products and …

The Influence Of Hip Mobility And Fatigue On Spinal Flexion And Muscle Activation In Rugby Scrum Performance, Joshua D. Clayton

Theses and Dissertations (Comprehensive)

Introduction: Rugby scrumming is a means of restarting play following a minor rule infringement that can occur up to 28 times per game. The scrum poses a significant injury risk, with more days missed due to injury per event than any other rugby activity. Rugby players also have a significantly higher rate of spine injury than the general population, perhaps due to flexion in combination with high compression forces, which has been cited as the main mechanism of injury. Flexion of the spine has also been associated with poor hip mobility and quadriceps fatigue in other athletic tasks and may …