Exercise Science Commons^™

The Effects Of Resistance Training On Strength And Body Composition In Postpartum Women, Katherine Bishop Pratt

Theses and Dissertations

The postpartum period represents a high-risk period for body weight retention and obesity. Several studies have investigated the role of aerobic exercise on postpartum weight retention and other body composition outcomes; however, there has been little attention given to resistance training in postpartum women. Thus, the purpose of this four-month randomized study was to determine the effectiveness of resistance training on strength, body composition, return to pre-pregnancy weight, and bone mineral density (BMD) in postpartum women. Sixty postpartum women were randomly assigned to either a resistance training group or a comparison group. The resistance training group participated in a progressive …

The Effect Of Resistance Training On Strength And Total Physical Activity In Postpartum Females, Tiffany Kaye Hinman

Theses and Dissertations

The purpose of this study was to compare strength and physical activity (PA) changes in postpartum women randomly assigned to either a four-month progressive resistance training (RT) program or a four month flexibility program. Sixty healthy women between six weeks and eight months postpartum initiated the study and 43 completed the entire study. The women tended to be overweight, were all non-smokers, and most were breastfeeding (97%) at the beginning of the study. Both groups (RT and flexibility) completed training exercises twice weekly. Both groups improved in all measures of strength (RT group: leg press, P < 0.001; bench press, P < 0.001; curl-ups, P < 0.001. Flexibility group: leg press, P = 0.009; bench press, P < 0.001; curl-ups, P = 0.005); however, the RT group had higher strength gains compared to the flexibility group over time (leg press, P < 0.005; bench press, P < 0.001; curl-ups, P < 0.007). In addition, both groups increased in low back flexibility but the group*period interaction did not reach significance (P = 0.096). Light-intensity PA increased in the RT group but not the flexibility group (P < 0.05). A group*period interaction was significant for light-intensity PA time (P = 0.031) and borderline significant for sedentary time (P = 0.054). However, controlling for the number of months postpartum and weight gain during the previous pregnancy resulted in a significant interaction for sedentary time (P < 0.05). No changes were found in moderate, vigorous, or moderate to vigorous PA within or between groups over time. In conclusion, twice-weekly RT increases strength and is associated with improvements in several PA outcomes in postpartum women; however, the mechanisms for this are unclear. The training sessions and/or increased spontaneous activity may have contributed.

The Role Of Nitric Oxide, Acetylcholine, And Vasoactive Intestinal Peptide On Skin Blood Flow During In-Vivo Electrical Field Stimulation, Robert S. Thiebaud

Theses and Dissertations

The purpose of this study was to characterize a novel technique to study neurogenic control of cutaneous vasodilation. We monitored skin blood flow (SkBF) during in-vivo electrical stimulation (e-stim) intended to activate cutaneous nerves and used intradermal microdialysis to deliver receptor antagonists to characterize their contribution to cutaneous vasodilation. We examined the role of acetylcholine receptors (RACh), nitric oxide (NO), and vasoactive intestinal peptide receptors (RVIP) on the cutaneous vasodilation induced by e-stim in the absence of the sympathetic adrenergic nervous system. Six men and three women participated in the study. Three intradermal microdialysis probes were placed in the skin …

The Role Of Movement Scaling On Quiet Eye Duration During An Aiming Task, Michelle Sachiko Okumura

Theses, Dissertations and Culminating Projects

No abstract provided.

Pre-Swing Deficits In Forward Propulsion, Swing Initiation And Power Generation By Individual Muscles In Hemiparetic Walking, Carrie L. Peterson, Allison Kinney, Steven A. Kautz, Richard R. Neptune

Mechanical and Aerospace Engineering Faculty Publications

Clinical studies of hemiparetic walking have shown pre-swing abnormalities in the paretic leg suggesting that paretic muscle contributions to important biomechanical walking subtasks are different than those of non-disabled individuals. Three-dimensional forward dynamics simulations of two representative hemiparetic subjects with different levels of walking function classified by self-selected walking speed (i.e., limited community=0.4–0.8 m/s and community walkers=>0.8 m/s) and a speed-matched control were generated to quantify individual muscle contributions to forward propulsion, swing initiation and power generation during the pre-swing phase (i.e., double support phase proceeding toe-off). Simulation analyses identified decreased paretic soleus and gastrocnemius contributions to forward propulsion …

Relationships Between Muscle Contributions To Walking Subtasks And Functional Walking Status In Persons With Post-Stroke Hemiparesis, Allison Kinney, Carrie L. Peterson, Steven A. Kautz, Richard R. Neptune

Mechanical and Aerospace Engineering Faculty Publications

Walking speed is commonly used to predict stroke severity and assess functional walking status (i.e., household, limited community and community walking status) post-stroke. The underlying mechanisms that limit walking speed (and functional walking status by extension) need to be understood to improve post-stroke rehabilitation. Previous experimental studies have shown correlations between paretic plantarflexor output during the pre-swing phase and walking speed and suggest that the paretic hip flexors can compensate in some hemiparetic subjects. Modeling and simulation studies of healthy walking have shown that the ankle plantarflexors, soleus (SOL) and gastrocnemius (GAS), and uniarticular hip flexors (IL) are essential contributors …

The Effects Of Low Frequency Ultrasound In Transdermal Drug Delivery, Aaron M. Wells

Theses and Dissertations

Objective: Determine if varying ultrasound frequency affects the delivery of 10% hydrocortisone concentrations during phonophoresis. Utilize intramuscular microdialysis probe for drug collection, thus improving the experimental model. Methods: Thirty one (10 in groups 1 and 2, 11 in group 3) healthy subjects participated in this study. Interventions: Subjects were randomly assigned to one of three treatment groups receiving 10 minute ultrasound treatments applied to a standardized area of the gastrocnemius muscle of the right leg. The ultrasound was performed over the treated area using a 10% hydrocortisone compound mixed with standard ultrasound gel. The contralateral limb served as the control …

The Effects Of Indoor Track Curve Radius On Sprint Speed And Ground Reaction Forces, Jesse Tipasa Tukuafu

Theses and Dissertations

Sprinting on a curve is significantly slower than on a straightaway. Although the dimensions vary from track to track, indoor track curves are among the tightest curves that athletes will sprint at maximal speed. Previous studies have provided theories for how speed attenuation occurs when running on a curve. Yet, no previous research has determined how the variability of indoor track curve radii affects trained sprinters at maximal speeds. Purpose: To determine the differences in running speeds, ground time (GT), and medio-lateral (ML) impulse, with different indoor track radii. A secondary purpose was to understand the between-leg differences in GT …

The Effect Of Lateral Spacing On The Spring Start, Kyle Louis Grossarth

Theses and Dissertations

Sprinters are always looking for an improvement in their time, from the gun going off until the finish. An effective start can lead to reaching top velocity sooner and a decreased finish time. New developments in starting blocks, more specifically the width of the starting block pedal, has allowed for variation in foot placement in the blocks. With the ability to change how wide an athlete can place their feet in the blocks, this study looked at trying to find an optimum spacing for college level sprinters. Thirteen Male College Sprinters (mean age = 23.08 years) participated in this study. …

Comparison Of Body Composition Between Physically Active And Inactive Wheelchair Users, Masaru Teramoto

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this study was to examine the association between regular physical activity and body composition in individuals with physical disabilities. The study was designed to compare body composition parameters between wheelchair users participating in adapted sports programs and those being physically inactive. Male wheelchair users were recruited and classified based on physical activity level (active or inactive) and disability type (paraplegic or quadriplegic). Regional and whole-body percent body fat (%BF), lean body mass (LBM), and bone mineral density (BMD) were assessed by dual-energy X-ray absorptiometry. These variables were then compared among the groups using a two-way between-groups multivariate …

High-Frequency Electrically Stimulated Skeletal Muscle Contractions Increase P70S6k Phosphorylation Independent Of Known Igf-I Sensitive Signaling Pathways, Sarah Witkowski, Richard M. Lovering, Espen E. Spangenburg

Exercise and Sport Studies: Faculty Publications

Insulin-like growth factor (IGF-I) is hypothesized to be a critical upstream regulator of mammalian target of rapamycin (mTOR)-regulated protein synthesis with muscle contraction. We utilized a mouse model that expresses a skeletal muscle specific dominant-negative IGF-I receptor to investigate the role of IGF-I signaling of protein synthesis in response to unilateral lengthening contractions (10 sets, 6 repetitions, 100. Hz) at 0 and 3. h following the stimulus. Our results indicate that one session of high frequency muscle contractions can activate mTOR signaling independent of signaling components directly downstream of the receptor.

Thrombin And Exercise Similarly Influence Expression Of Cell Cycle Genes In Cultured Putative Endothelial Progenitor Cells, Michael M. Lockard, Sarah Witkowski, Nathan T. Jenkins, Espen E. Spangenburg, Thomas O. Obisesan, James M. Hagberg

Exercise and Sport Studies: Faculty Publications

Acute exercise and exercise training may influence putative endothelial progenitor cell (EPC) number and colony forming units (CFU-ECs), although the mechanisms remain unclear. This study examined the effects of in vitro thrombin supplementation and acute exercise on CFU-EC gene expression, associated with cellular proliferation and differentiation. The effect of habitual physical activity was evaluated through analysis of EPCs from chronically high- and low-active men. Participants were healthy high- and low-active men (n = 23), aged 55-80 yr. Circulating CD34+/VEGFR2+ number, CFU-ECs, plasma prothrombin fragment (F1+2), and thrombin-antithrombin III were measured at rest and after 30 min of exercise. Gene expression …

Comparison Of A Reduced Carbohydrate And Reduced Fat Diet For Ldl, Hdl, And Vldl Subclasses During 9-Months Of Weight Maintenance Subsequent To Weight Loss, James D. Lecheminant, Bryan K. Smith, Eric C. Westman, Mary C. Vernon, Joseph E. Donnelly

Faculty Publications

Objectives: This study compared LDL, HDL, and VLDL subclasses in overweight or obese adults consuming either a reduced carbohydrate (RC) or reduced fat (RF) weight maintenance diet for 9 months following significant weight loss. Methods: Thirty-five (21 RC; 14 RF) overweight or obese middle-aged adults completed a 1-year weight management clinic. Participants met weekly for the first six months and bi-weekly thereafter. Meetings included instruction for diet, physical activity, and behavior change related to weight management. Additionally, participants followed a liquid very low-energy diet of ~2092 kJ per day for the first three months of the study. Subsequently, participants followed …

Resistance Training Increases The Expression Of Ampk, Mtor, And Glut4 In Previously Sedentary Subjects And Subjects With The Metabolic Syndrome., Andrew Steven Layne

Electronic Theses and Dissertations

Exercise has been considered a cornerstone of diabetes prevention and treatment for decades, but the benefits of resistance training are less clear. Nineteen non-diabetic subjects (10 metabolic syndrome, 9 sedentary controls) underwent 8 weeks of supervised resistance training. After training, strength and V̇ O_2max increased by 10% in both groups. Percent body fat decreased in subjects with the metabolic syndrome. Additionally, lean body mass increased in both groups (p<0.05). Expression of glucose transporter protein-4 (GLUT4), the principle insulin-responsive glucose transporter, increased significantly in both groups. 5-adenosine monophosphateactivated protein kinase (AMPK) and mammalian target of rapamycin (mTOR) expression increased in both groups, indicating increased protein synthesis and mitochondrial biogenesis. Markers of insulin resistance measured by a euglycemic hyperinsulinemic clamp did not improve in subjects with the metabolic syndrome but increased significantly in control subjects (13%). Resistance training upregulates intracellular signaling pathways that may be beneficial for ameliorating the metabolic syndrome.

Research Associations Between Sport And Screen-Entertainment With Mental Health Problems In 5-Year-Old Children, Lucy J. Griffiths, Marsha Dowda, Carol Dezateux, Russell R. Pate

Faculty Publications

Background: Few studies have examined the benefits of regular physical activity, and risks of sedentary behaviour, in young children. This study investigated associations between participation in sports and screen-entertainment (as components of physical activity and sedentary behaviour), and emotional and behavioural problems in this population.

Methods: Cross-sectional analysis of data from 13470 children (50.9% boys) participating in the nationally representative UK Millennium Cohort Study. Time spent participating in sports clubs outside of school, and using screen-entertainment, was reported by the child's mother at child age 5 years, when mental health was also measured using the Strengths and Difficulties Questionnaire.

Results: …

Neuromechanical Analysis Of Anterior Cruciate Ligament Risk Factors In Female Collegiate Soccer Athletes, Nelson Cortes

Human Movement Studies & Special Education Theses & Dissertations

The anterior cruciate ligament (ACL) acts in an essential role to prevent anterior tibial displacement when experiencing jump-landing forces that are applied to the lower extremity; more than 100,000 injuries per year in the United States in sport activities that often require landing, deceleration-acceleration, cutting and pivoting actions have been reported. The aim of this study was to examine the nature of any lower limb coupling differences between a drop-jump and a side-step cutting actions, assess kinematic and kinetic differences between three tasks, and evaluate the effects of two landing techniques in biomechanical risk factors while performing two unanticipated tasks. …

The Effects Of Two Different Fatigue Protocols On Lower Extremity Kinematics And Kinetics During An Unanticipated Running Stop-Jump, David L. Quammen

Human Movement Studies & Special Education Theses & Dissertations

Altered neuromuscular control strategies and biomechanical movement risk factors are most likely to contribute to the increased incidence of non-contact ACL injury for female athletes. Neuromuscular control strategies and movement patterns are further altered when the effects of fatigue are present. The purpose of this study was to determine neuromechanical differences between two fatigue protocols [Slow Linear Oxidative Fatigue Protocol (SLO-FP) and Functional Agility Short-Term Fatigue Protocol (FASTFP)] when performing a running stop-jump task (RS). A sample of convenience of fifteen Division I female soccer players (age= 19.2 ± 0.8 years; height= 1.67 ± 0.05 m; mass= 61.7 ± 8.1 …

The Correlation Between Visual Observations And Inclinometric Measurements For Special Tests Related To Patellofemoral Pain Syndrome, Erin Quada

Human Movement Studies & Special Education Theses & Dissertations

Patellofemoral pain syndrome (PFPS) is generally described as an insidious onset with pain increasing during running, jumping, ascending and descending stairs as well as sitting with the knees flexed for an extended period of time. Clinicians often use special tests in injury evaluations and range of motion assessments, usually making a visual observation of that status of the patient. The purpose of this study was to examine how interval measurements utilized in flexibility and range of motion assessments correlate with visual observations of special tests (active knee extension test, Thomas test, Ober's test, rectus femoris flexibility, and Craig's test). The …

The Effects Of An Anterior Cruciate Ligament Prevention Program And Retention Period On Lower Extremity Biomechanics, Ryan S. Mccann

Human Movement Studies & Special Education Theses & Dissertations

Researchers have attempted to determine the effects of strength, flexibility, agility, and plyometric training, as well as expert feedback on biomechanical risk factors for anterior cruciate ligament (ACL) injuries. Currently, the literature lacks information regarding athletes' ability to retain adaptations made during programs designed to reduce biomechanical risk factors for ACL injuries. The purpose of this study was to determine the effects of a 10-week strength and agility program on lower extremity kinetics and kinematics of collegiate athletes immediately following training and after a 11-week retention period. Ten NCAA Division I female soccer players free of lower extremity injury, volunteered …

The Effects Of Two Types Of Fatigue On An Unanticipated Side-Step Cutting Task As Measured By Kinematic And Kinetic Variables, Shawn E. Lucci

Human Movement Studies & Special Education Theses & Dissertations

Fatigue has been shown to alter the neuromechanics of lower extremity. To date, no study has examined the effects of two types of fatigue on kinetics and kinematics. To determine neuromechanical differences between two fatigue protocols [Slow Linear Oxidative Fatigue Protocol (SLO-FP) and Functional Agility Short-Term Fatigue Protocol (FAST-FP)] when performing an unanticipated sidestep cutting task. Fifteen female collegiate soccer players (age=19.2±0.8 years; height=l.67±0.05m; mass=61.7±8.lkg) participated in this study. Participants were free of lower extremity injury at time of participation, and performed five successful trials of a sidestep cutting (SS) task pre and post fatigue protocols. For the SLO-FP, a …