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Exercise Science

Theses/Dissertations

2013

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Pharmacokinetics Of Dexamethasone Delivered Via Iontophoresis, Justin Holbrook Rigby Dec 2013

Pharmacokinetics Of Dexamethasone Delivered Via Iontophoresis, Justin Holbrook Rigby

Theses and Dissertations

Study Design: Controlled laboratory study. Objectives: To determine the time course of dexamethasone sodium phosphate (Dex-P) iontophoresis delivery to underlying tissues using microdialysis. Background: The efficacy of iontophoresis at delivering Dex-P through the skin is unknown in humans because of the lack of minimally invasive measurement techniques. Methods: Sixty-four healthy male participants (age = 24.4 ± 3.3 yrs, height = 71.8 ± 2.5 in, weight = 181.8 ± 26.1 lbs) were randomly assigned into one of six groups: 1) 1 mA current, 1 mm probes depth ; 2) 1 mA current, 4 mm probes depth; 3) 2 mA current, 1 …


The Acute Effects Of Whole-Body Vibration Training On Passive And Dynamic Flexibility In Gymnasts, Caisa Nicole Brooks Dec 2013

The Acute Effects Of Whole-Body Vibration Training On Passive And Dynamic Flexibility In Gymnasts, Caisa Nicole Brooks

Theses and Dissertations

Gymnasts must attain extreme ranges of flexibility to execute performance requirements, thus effective stretching proves vital to advancement in the sport. This study examined the acute effects of whole-body vibration (WBV) on passive and dynamic flexibility in young, female gymnasts. Participants (n = 27, Junior Olympic levels 5-10) served as their own control. Measurements of passive and dynamic flexibility were obtained using the TOPS forward split testing method to examine passive flexibility and dynamic flexibility was measured via split jumps that were analyzed with video and Dartfish software. According to randomized order, all participants completed a stretching protocol either with …


Obm Thesis Project: Composing An Undergraduate Thesis Manual, William Strong Dec 2013

Obm Thesis Project: Composing An Undergraduate Thesis Manual, William Strong

Honors Theses

The Behavioral Research Supervisory System (BRSS) is a class designed to assist undergraduate and master students in completing a thesis project in a timely manner. Prior to beginning this project, undergraduate students were not utilizing the thesis manual for the class effectively and master students did not have an effective tool to grade the quality of their undergraduate thesis students’ work. Therefore, the ultimate goal of this thesis project is to create a better manual for undergraduate students to reference while working on their thesis projects and to provide a systematic grading system for their graduate student supervisors. A pre-manual …


The Effect Of Wild Blueberry Consumption On The Inflammatory Response, Oxidative Stress And Dna Damage Associated With Exercise, Taylor K. Bloedon Dec 2013

The Effect Of Wild Blueberry Consumption On The Inflammatory Response, Oxidative Stress And Dna Damage Associated With Exercise, Taylor K. Bloedon

Electronic Theses and Dissertations

At all levels of intensity and duration, exercise is known to cause an increase in the generation of reactive oxygen species (ROS). When derivatives of oxygen occur and exist independently with one or more unpaired electrons they are known as “free radicals” (Halliwell and Gutteridge 2007). Since atoms possess electrons that are usually associated in pairs, free radicals have the potential to act negatively in the body. Reactive oxygen species refer to oxygen-centered radicals as well as nonradical but reactive derivatives of oxygen (Halliwell and Gutteridge 2007). When ROS are created in excess, resulting in the disruption of the pro-oxidant/antioxidant …


Racial Differences In Self-Efficacy Expectations For Exercise, Selena P. Smith Dec 2013

Racial Differences In Self-Efficacy Expectations For Exercise, Selena P. Smith

Honors Theses

This project examined the link between race and self-efficacy. Self-efficacy pertains to an individual’s confidence in ability to complete or engage in a particular task or activity (Bandura, 1986). Prior research shows that self-efficacy has a great influence on exercise initiation and adherence (Bandura, 1986; Dishman, 1982; Rodgers and Sullivan, 2001). Research also supports that Caucasians are more likely to participate in exercise than African Americans (Centers for Disease Control and Prevention, 2000).

Participants included 51 females, 31 Caucasians and 20 African Americans, between the ages of 18 and 50 years old. The women were recruited from local fitness gyms, …


Evaluation Of Shake Weight Protocol In Senior Populations, Isaac F. Cook Dec 2013

Evaluation Of Shake Weight Protocol In Senior Populations, Isaac F. Cook

Graduate Theses and Dissertations

The Shake Weight® (SW®) is designed to improve muscular fitness in a quick and inexpensive way. This study aimed to determine if the SW® was an effective tool at improving muscular fitness, body composition, and bone mineral density (BMD) in post-menopausal women. Participants were 17 healthy, post-menopausal women from aMidwestern University and divided into two training (SW® and HIT) interventions that lasted 10 weeks. HIT participants performed three sets of 8 repetitions at 80% of their estimated 1RM for the chest press, leg press, lat pulldown, and seated row. SW® participants performed the exercises prescribed by the SW® manufacturer. Changes …


Post-Exercise And Post-Recovery Blood Lactate In Peripheral Arterial Disease, Rebecca Kate Roderick Dec 2013

Post-Exercise And Post-Recovery Blood Lactate In Peripheral Arterial Disease, Rebecca Kate Roderick

Graduate Theses and Dissertations

The purpose of this study was to observe how the presence of peripheral arterial disease affects the level of post-exercise blood lactate and post-recovery blood lactate during and following the six-minute walk test (6MWT). The 6MWT was administered to 49 participants (33 classified as Non-PAD and 16 classified as PAD) over the age of 50 with no uncontrolled cardiovascular or metabolic diseases or a cardiovascular event in the previous 6 months. Results demonstrated that no significant statistical difference exists between the presence of PAD and resting blood lactate (F = 0.86, p = .36), post-exercise blood lactate (F= 0.48, p …


Regulation Of The Myostatin Protein In Overload-Induced Hypertrophied Rat Skeletal Muscle, Paige Abriel Affleck Dec 2013

Regulation Of The Myostatin Protein In Overload-Induced Hypertrophied Rat Skeletal Muscle, Paige Abriel Affleck

Theses and Dissertations

Myostatin (GDF-8) is the chief chalone in skeletal muscle and negatively controls adult skeletal muscle growth. The role of myostatin during overload-induced hypertrophy of adult muscle is unclear. We tested the hypothesis that overloaded adult rodent skeletal muscle would result in reduced myostatin protein levels. Overload-induced hypertrophy was accomplished by unilateral tenotomy of the gastrocnemius tendon in male adult Sprague-Dawley rats followed by a two-week period of compensatory overload of the plantaris and soleus muscles. Western blot analysis was performed to evaluate changes in active, latent and precursor myostatin protein levels. Significant hypertrophy was noted in the plantaris (494 ± …


Seasonal Changes In Body Composition, Block Jump, Attack Jump And Lower Body Power Index In Male Collegiate Volleyball Players, Geoffrey W. Loomis Dec 2013

Seasonal Changes In Body Composition, Block Jump, Attack Jump And Lower Body Power Index In Male Collegiate Volleyball Players, Geoffrey W. Loomis

Theses and Dissertations

Jumping ability in volleyball players is crucial to a team's success. There are both muscular and neural components in jumping. Coaches often test jumping ability and body composition prior to the start of the competitive season, but many fail to monitor these important variables during the course of the season. Jumping ability can decrease over the course of the season as the focus moves from strength training in the weight room to skill development on the court. It is imperative that players maintain their jumping ability and body composition over the course of the season. Seasonal changes in elite-male volleyball …


The Effects Of 8 Weeks Of Low Dose Supplementation Of Creatine And Sodium Bicarbonate On Exercise Performance, Amanda Jessica Morris Dec 2013

The Effects Of 8 Weeks Of Low Dose Supplementation Of Creatine And Sodium Bicarbonate On Exercise Performance, Amanda Jessica Morris

Master's Theses

Short-term (3-7 days), high doses of creatine (20g/d) and/or sodium bicarbonate (0.5g/kg body weight) supplementation increase exercise performance during short term high intensity activities; however, it remains unclear whether long-term, low doses of these supplements have a positive impact on exercise performance. The purpose of this study was to determine the effects of long-term (8 weeks), low dose creatine supplementation on exercise performance, and whether combining creatine and sodium bicarbonate supplementation has an additive effect. Sixty-three healthy, habitually active, adults (28 M, 35 W; 22+2 years; 23+ 3 BMI) were randomly assigned by sex to one of three supplement groups: …


Variability Of Practice And Strength Training Periodization: When Theories Collide, Katherine Lauren Streder Dec 2013

Variability Of Practice And Strength Training Periodization: When Theories Collide, Katherine Lauren Streder

Master's Theses

The primary purpose of this study was to examine whether variability of practice enhances neuromuscular adaptations when compared to traditional strength training. The secondary purpose was to investigate whether there was a difference in perception of exertion between the two strength programs. Forty one subjects (23 women and 18 men) were assigned to either the control group or one of two treatment groups by a blocked-random method. Subject's one repetition maximum (1RM) for the kettlebell press and leg press were measured at baseline, after 4 weeks of training, and after 8 weeks of training. The treatment groups completed 8 weeks …


The Association Between Dairy Consumption And Insulin Resistance, Andrea Rose Erickson Nov 2013

The Association Between Dairy Consumption And Insulin Resistance, Andrea Rose Erickson

Theses and Dissertations

Background: A cross-sectional design was employed to ascertain the relationship between dairy consumption and insulin resistance (IR) in 272 middle-aged, nondiabetic women. Methods: Participants kept a seven-day weighed food record to report their diets, including consumption of dairy foods. IR was assessed using the homeostatic model assessment (HOMA), using the following formula: fasting plasma insulin (µU/ml) x fasting plasma glucose (mg/dL)/405. The Bod Pod was used to examine body fat percentage, and accelerometry over a seven-day period was used to assess physical activity. HOMA values were log-transformed and regression analysis and the General Linear Model procedure were used to determine …


The Relationship Between Television Viewing Time And Cardiorespiratory Fitness In Adult Women, Peter Jacob Arens Nov 2013

The Relationship Between Television Viewing Time And Cardiorespiratory Fitness In Adult Women, Peter Jacob Arens

Theses and Dissertations

Purpose: The present investigation was conducted to assess the relationship between television viewing time and cardiorespiratory fitness. Design: Cross-sectional. Setting: Intermountain West. Participants: 302 middle-aged women. Method: TV viewing was assessed using a questionnaire. Cardiorespiratory fitness was measured using a maximal graded treadmill test. Physical activity (PA) was evaluated using Actigraph accelerometers worn over seven consecutive days, while body fat percentage (BF%) was measured using air displacement plethysmography (Bod Pod). Results: (Mean ± SD) age: 40.2 ± 3.0 years. VO2max of the frequent (≥ 3hrs/day) TV group (32.6 ± 6.4) was significantly lower than both the moderate (1-2 hrs/day) (36.2 …


Hemodynamic And Neuromuscular Responses To Exercises Performed On Stable And Unstable Surface With And Without Blood Flow Restriction, Agnelia Tiffany Hernandez Nov 2013

Hemodynamic And Neuromuscular Responses To Exercises Performed On Stable And Unstable Surface With And Without Blood Flow Restriction, Agnelia Tiffany Hernandez

Theses and Dissertations - UTB/UTPA

PURPOSE: The aim of this study was to investigate the acute effects of circuit training exercises on stable and unstable surface with and without blood flow restriction (BFR) on several physiological measures (heart rate, blood pressure, muscle unit activation and rate of perceived exertion).

METHODS: Sixteen recreationally active, males (age= 24.3 ± 1.2); n=8) and females (age= 23.1 ± 0.9); n=8) completed four testing sessions, no blood flow restriction (NBFR) on a stable surface, NBFR on an unstable surface, BFR on a stable surface, and BFR on an unstable surface. Participants performed lower body exercises in a circuit like …


The Relationship Between Subjectively Motivational Music And Various Exercise Variables While Running At Maximal Speed, Michael Maloney Oct 2013

The Relationship Between Subjectively Motivational Music And Various Exercise Variables While Running At Maximal Speed, Michael Maloney

Honors College Theses

Purpose: To determine whether there are differences in steps/min/m, highest achieved exercise heart rate, average exercise heart rate, average running speed, estimated relative VO2, and RPE, while listening to subjectively motivating music, as compared to non-motivating music, while running at max speed. Methods: Eleven students enrolled at the University of Massachusetts Boston, considered “non-runners” from 19 to 34 years of age, ran at max speeds for 12-15 minutes, once while listening to a play-list of songs they ranked most motivating, and a second time on a separate day, while listening to a play-list of songs they ranked least …


A Comparison Of Two Sock Types On Navicular Drop And Center Of Pressure Measurements In Standing, Walking, And Running, Ashlee Taylor Sep 2013

A Comparison Of Two Sock Types On Navicular Drop And Center Of Pressure Measurements In Standing, Walking, And Running, Ashlee Taylor

Theses and Dissertations

Introduction: The New Balance Core Low Cut Sock (New Balance Athletic Shoe, Inc. · Boston, MA United States) is one of many arch support socks out in the market. These socks have an elastic portion, called a Stability Fit Arch Support & Hold technology, which has been incorporated into the arch area of the sock. The company makes the following claim that the socks provide, "Gentle compression to support the arch, relieving arch-related pain and discomfort."1 If these socks do provide adequate arch support, then they would allow individuals the ability to have an inexpensive method of arch support that …


A Six Week Modified Sprint Interval Training Program Incorporating Extended Exercise Bouts Does Not Increase Maximal Cardiac Output, Alan R. Smith Sep 2013

A Six Week Modified Sprint Interval Training Program Incorporating Extended Exercise Bouts Does Not Increase Maximal Cardiac Output, Alan R. Smith

Electronic Thesis and Dissertation Repository

Sprint interval training (SIT) improves maximal oxygen uptake (V̇O2max) and exercise performance but not maximal cardiac output (Q̇max). The brevity of typical SIT bouts (30-seconds) might hinder improvements in Q̇max. The purpose of this study was to determine whether extended duration SIT (up to 45 second bouts) improves Q̇max. Pre-/Post-SIT (or control) V̇O2max, Q̇max, maximum stroke volume (SVmax), maximum heart rate, arterial-mixed venous oxygen difference, and 5-minute run distance were measured. SIT progressed from 4x30s to 7x45s “all-out” efforts (4 min recovery) over 6 wk (3x/wk) …


A Quantitative Emg Assessment Of Motor Unit Recruitment In Patients With Ulnar Neuropathy, Kayla N. Ryan Sep 2013

A Quantitative Emg Assessment Of Motor Unit Recruitment In Patients With Ulnar Neuropathy, Kayla N. Ryan

Electronic Thesis and Dissertation Repository

The aim of the current study was to assess the test – retest reliability of motor unit firing rates with the use of decomposition based quantitative electromyography, and to quantify motor unit firing rates in the first dorsal interosseous of patients with ulnar neuropathy. 8 healthy subjects (mean age 35 ± 10 years) and 8 patients (mean age 48 ± 10 years) with ulnar neuropathy participated in the study. Following the acquisition of a maximum M wave, needle and surface detected EMGs were collected simultaneously during 30-second contractions performed at threshold (1-2% maximum voluntary contraction (MVC)) and 10% MVC- RMS …


The Effects Of Long-Term Physical Activity On Food Attention Allocation In College Freshmen Women, Sharla Elizabeth Compton Sep 2013

The Effects Of Long-Term Physical Activity On Food Attention Allocation In College Freshmen Women, Sharla Elizabeth Compton

Theses and Dissertations

Purpose: The purpose of this study was to examine the effects of long-term (24 weeks) physical activity on attention allocated toward food in college freshmen women. Methods: Seventy-nine freshmen college women wore a multi-function pedometer for 24 weeks after being randomly assigned to a daily step level: 10,000; 12,500; or 15,000. After at least 16 weeks of intervention, participants were given a cognitive viewing task (pictures of food and flowers) with the neural response measured using electroencephalogram (EEG) and event-related potentials (ERPs). P300s and LPPs are components of the ERP indicating increased attention to stimuli. Results: There was a significant …


Electromechanical Delay Of The Dorsiflexors In Young And Old Women, In H. Choi Sep 2013

Electromechanical Delay Of The Dorsiflexors In Young And Old Women, In H. Choi

Electronic Thesis and Dissertation Repository

PURPOSE: The aim of the current study was to examine the effect on electromechanical delay (EMD) in the dorsiflexors of young and old women during maximal isometric voluntary and electrically evoked contractions, and after a bout of lengthening contractions. METHODS: Nine young (25.1±1.3 years) and nine old (68.3±6.1 years) women performed baseline isometric contractions with evoked twitches followed by a series of dynamic lengthening contractions using a Biodex multi-joint dynamometer. Maximal isometric voluntary and evoked contractions were measured to assess EMD. Time points were recorded at baseline, mid-point of the intervention, post-task termination, and during recovery at 0.5, 2, 10, …


The Effect Of Low And High Carbohydrate Diets On Pulmonary Oxygen Uptake And Muscle Deoxygenation Kinetics During Exercise Transitions Into The Heavy-Intensity Domain, John Leckie Aug 2013

The Effect Of Low And High Carbohydrate Diets On Pulmonary Oxygen Uptake And Muscle Deoxygenation Kinetics During Exercise Transitions Into The Heavy-Intensity Domain, John Leckie

Electronic Thesis and Dissertation Repository

The purpose of this study was to determine the effects of a high carbohydrate (HCHO) and low carbohydrate (LCHO) diet on the adjustment of pulmonary oxygen (O2) uptake ( ) and muscle deoxygenation ([HHb]) during transitions to heavy intensity exercise. Young, healthy, male subjects aged (24+/-3) underwent a 4 day LCHO followed immediately by a 4 day HCHO diet, with each diet preceded by a glycogen depletion protocol. This protocol was designed to alter PDH activity. Subjects completed 3 step transitions to a work rate corresponding to 35% of the difference between their lactate threshold and peak for …


Adjustment Of Pulmonary O2 Uptake, Muscle Deoxygenation And Metabolism During Moderate-Intensity Exercise Transitions Initiated From Low And Elevated Baseline Metabolic Rates, Joshua P. Nederveen Aug 2013

Adjustment Of Pulmonary O2 Uptake, Muscle Deoxygenation And Metabolism During Moderate-Intensity Exercise Transitions Initiated From Low And Elevated Baseline Metabolic Rates, Joshua P. Nederveen

Electronic Thesis and Dissertation Repository

When instantaneous step-wise transitions within the moderate intensity domain are initiated from elevated metabolic rates, the rate of pulmonary oxygen uptake (V̇O2p) adjustment is slowed, and the V̇O2p gain (ΔV̇O2p /ΔWR) is greater. This study sought to determine the relationship between V̇O2p kinetics and metabolic activity and energy status during step transitions from low and elevated metabolic rates within the moderate intensity domain. Ten young men completed six double-step constant load cycling bouts, consisting of step-wise transitions from 20 W to 45% θL and 45% θL [lower step (LS)] to 90% θL …


Role Of Adenylyl Cyclase S674 In Central And Forearm Vasomotor Control, James Corkal Aug 2013

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 …


The Effect Of Exercise On Cravings And Ad Libitum Smoking Following Concurrent Stressors, Angela J. Fong Aug 2013

The Effect Of Exercise On Cravings And Ad Libitum Smoking Following Concurrent Stressors, Angela J. Fong

Electronic Thesis and Dissertation Repository

Quitting smoking itself is a stressor; it is likely that other stressors occur concurrently and deplete self-regulatory resources. Failure to cope leads to smoking relapse. Exercise has been shown to attenuate cravings and withdrawal symptoms in previous research and has yet to be examined following concurrent stressors. This study examined the effect of an acute bout of moderate intensity exercise on psychological withdrawal symptoms (PWS), cravings and ad lib smoking after concurrent stressors (i.e., temporary abstinence and depletion). Twenty-five smokers were randomized into exercise or passive conditions. Results showed PWS were significantly exacerbated after temporary abstinence and again after depletion …


The Effects Of A Moisture-Wicking Fabric Shirt On The Physiological Responses During Acute Exercise In The Heat, Kimberly Wigboldy Aug 2013

The Effects Of A Moisture-Wicking Fabric Shirt On The Physiological Responses During Acute Exercise In The Heat, Kimberly Wigboldy

Masters Theses

The purpose of this study is to investigate the effects that a form fitted, moisture-wicking fabric shirt, promoted to have improved evaporative and ventilation properties, has on the thermoregulatory, physiological and perceptual response during moderate intensity exercise in the heat for an extended duration of exercise of 90 minutes. Ten healthy subjects (7 males, 3 females), completed two heat stress tests consisting of 20 minute seated rest in a neutral environment (24°C, 60% RH), 30 minute seated rest in a hot environment (33°C, 60% RH), and 90 minutes of exercise(50% V02 peak) on a magnetically-braked cycle ergometerin a …


Effects Of High-Velocity Versus Low-Velocity Resistance Training On Resting Metabolic Rate And Functional Performance In Older Adults, Laura Ashleigh Morgan Aug 2013

Effects Of High-Velocity Versus Low-Velocity Resistance Training On Resting Metabolic Rate And Functional Performance In Older Adults, Laura Ashleigh Morgan

Graduate Theses and Dissertations

The purpose of this study was to compare the effects of a 12-week high-velocity resistance training (HVRT) protocol to a traditional low-velocity resistance training (LVRT) protocol on resting metabolic rate (RMR) and other selected measures of muscular and functional fitness in older adults. Nineteen adults between the ages of 65 and 82 participated: 8 HVRT, 7 LVRT, and 4 controls (CTRL). Initially, no differences existed between groups except for age (p = .016). HVRT (75.6 years) was older than LVRT (69.6 years) and CTRL (69.3 years). The exercise intervention consisted of 2 days/week sessions for 12 weeks at 3 sets …


Exercise Participation During Weight Loss On A High Protein – Low Carbohydrate Diet Plan In Females Aged 15-25 Years, Margaret Mobley-Meulman Aug 2013

Exercise Participation During Weight Loss On A High Protein – Low Carbohydrate Diet Plan In Females Aged 15-25 Years, Margaret Mobley-Meulman

Electronic Theses and Dissertations

Weight gain due to poor diet and lack of exercise is responsible for over 300,000 deaths each year (U.S. Department of Health and Human Services, 2010). Obese adults have an increased risk for serious health conditions including high blood pressure and cholesterol, type 2 diabetes, coronary heart disease, stroke, gallbladder disease, osteoarthritis, sleep apnea, respiratory problems, and certain cancers (National Cancer Institute, 2012). Participation in exercise can help control weight, strengthen muscles and bones, and reduce the incidence of cardiac events, stroke, hypertension, type 2 diabetes, colon and breast cancers, osteoporotic fractures, gallbladder disease, obesity, depression, anxiety, and delay mortality …


Relationship Of Global Dna Methylation With Cardiovascular Fitness And Body Composition, Michael Steele Jarrett Aug 2013

Relationship Of Global Dna Methylation With Cardiovascular Fitness And Body Composition, Michael Steele Jarrett

UNLV Theses, Dissertations, Professional Papers, and Capstones

Background: Global DNA Methylation (GDM), an epigenomic modification has been linked to the development of Cardiovascular Disease and its risk factors. Purpose: The purpose of this study was to determine if there is a significant correlation between GDM and cardiovascular fitness, as well as, measures of body composition. Methodology: 26 apparently healthy, adults (11 males) completed a physical activity and diet questionnaire, as well as, had a small blood sample (600μL) collected via finger prick for the determination of GDM. Body composition was assessed by means of a Dual-Energy X-ray Absorptiometry (DEXA) scan, while cardiovascular fitness was evaluated by the …


Somatosensory Stimulation Modulates Heart Rate Variability Changes Induced By Isometric Handgrip Exercise, Jacquie Baker Jul 2013

Somatosensory Stimulation Modulates Heart Rate Variability Changes Induced By Isometric Handgrip Exercise, Jacquie Baker

Electronic Thesis and Dissertation Repository

Functional imaging reveals overlapping forebrain and basal ganglia regions associated with heart rate (HR) and heart rate variability (HRV) regulation. Somatosensory stimulation (STIM) and isometric handgrip (HG) were used to test the hypotheses that a) STIM would modulate HG-induced changes to HR and HRV, and b) HG+STIM would produce different cortical activation relative to HG alone (n=12). During STIM, high-frequency (HF)-HRV increased (p<0.05), whereas HR did not change. During HG, HF-HRV decreased (p<0.01) while HR increased (p<0.001). HG+STIM reversed the HG-induced change in HF-HRV (p<0.01). However, the HR response to HG remained unaffected. HG increased insular activation, while ventral medial prefrontal cortex (vMPFC) activity decreased. HG+STIM produced similar vMPFC deactivation. However, insular activation was no longer evident. These data indicate that somatosensory inputs through STIM can modulate HG-induced changes to HF-HRV. Different insular activations during HG versus HG+STIM suggest afferent signals to the insula may inhibit descending motor signals affecting HF-HRV.


Plasma Lactate Accumulation During Running With Body Weight Unloading By Lbpp, Nicole Nevitt Rasmussen Jul 2013

Plasma Lactate Accumulation During Running With Body Weight Unloading By Lbpp, Nicole Nevitt Rasmussen

Theses and Dissertations

At any given running speed, weight support with a lower body positive pressure (LBPP) device (i.e. Alter-G treadmill) reduces V̇O2. However, it is unknown how application of LBPP during running impacts lactate metabolism, specifically lactate threshold. Purpose: To determine if body weight unloading with the Alter-G treadmill alters lactate threshold. Methods. Maximal aerobic capacity (V̇O2max) and lactate threshold (LT) was determined in 8 male subjects on an Alter-G treadmill at 100% and 80% body weight loading at 0% grade in a randomized crossover design. V̇O2max tests started at 7 mile h-1 and increase speed by 1 mile h-1 every 2 …