Master of Science / Department of Kinesiology / Craig A. Harms / An increased work of breathing during heavy whole body exercise can lead to respiratory muscle fatigue (RMF) and decreased leg blood flow. Heavy exercise also increases inactive limb and cutaneous blood flow. It is not known, however, how RMF affects inactive limb and cutaneous blood flow. Therefore, we tested the hypothesis that RMF during heavy exercise would reduce: 1) inactive limb blood flow, 2) inactive limb vascular conductance, and 3) inactive limb cutaneous blood flow. Twelve healthy men (23 ± 2 yrs) completed baseline pulmonary function tests followed by an incremental cycle test to VO[subscript]2[subscript]max. Subjects then cycled at both 70% and 85%VO2max (randomized) for 20 minutes. Subjects performed a second 85%VO[subscript]2[subscript]max test ingesting N-acetylcysteine (NAC) (1800mg), which has been reported to reduce RMF, 45 minutes prior the test. Maximum inspiratory pressures (P[subscript]Imax) were measured prior to and immediately following each exercise trial to determine RMF. During exercise, brachial artery blood flow (BABF) was measured via Doppler ultrasound and arm cutaneous blood flow was assessed by laser-Doppler flowmetry. Cutaneous vascular conductance (CVC) was calculated as flux/mean arterial pressure and scaled as % maximal CVC (sites heated to 46[degrees]C). Mean arterial pressure (MAP) was measured manually. Significant RMF occurred with 85%VO[subscript]2[subscript]max (12.8 ± 9.8%), but not with 70%VO[subscript]2[subscript]max (p>0.05). BABF significantly increased from baseline to end exercise in both conditions and was significantly lower (~18%) following the 85%VO[subscript]2[subscript]max test. The amount of RMF at 85%VO[subscript]2[subscript]max was inversely related to the change in BABF (r= -0.66, p<0.05). BA vascular conductance was significantly higher at end exercise at 70%VO[subscript]2[subscript]max compared to 85%VO[subscript]2[subscript]max (2.60 ± 0.73 vs. 2.00 ± 0.42 mLmin[superscript]-1mmHg[superscript]-1, resp.). The amount of RMF at 85%VO[subscript]2[subscript]max was inversely related to BA vascular conductance at end exercise (r= -0.80, p<0.05). Cutaneous vascular conductance was not different (p>0.05) between trials. With NAC, RMF was reduced and BABF was consequently significantly higher (~30%) compared to 85%VO[subscript]2[subscript]max. These data suggest that RMF during heavy whole body exercise decreases inactive arm blood flow and vascular conductance, but not cutaneous blood flow.

Master of Science / Department of Kinesiology / Brett J. Wong / Mechanisms underlying the cutaneous vasodilation response to local skin heating and whole body heating in humans remain unresolved. Although nitric oxide (NO) is known to contribute to these responses, it remains unclear as to the source of NO. Adenosine receptors induce vasodilation in many human tissues and may work, in part, through NO. As these receptors are also known to be located in the cutaneous vasculature, the studies contained in this thesis were designed to investigate a potential contribution of adenosine receptor activation to the rise in skin blood flow elicited by local skin and whole body heating. The study presented in chapter IV was designed to determine a potential role for adenosine receptors in contributing to cutaneous thermal hyperemia. Four cutaneous microdialysis sites were randomly assigned one of four drug treatments designed to elucidate the contribution of A[subscript]1/A[subscript]2 adenosine receptors during local skin heating. Each site was locally heated from a baseline temperature of 33°C to 42°C at a rate of 1°C/10 s and skin blood flow was monitored via laser-Doppler flowmetry (LDF). The data obtained from these experiments suggest A[subscript]1/A[subscript]2 adenosine receptor activation directly contributes to cutaneous thermal hyperemia. These data further suggest a portion of the NO response may be explained by A[subscript]1/A[subscript]2 adenosine receptor activation; however, a substantial portion of the NO response is independent of the adenosine receptor contribution. The study presented in chapter V was designed to determine a potential role for A[subscript]1/A[subscript]2 adenosine receptors in contributing to cutaneous active vasodilation. Four cutaneous microdialysis sites were randomly assigned one of four drug treatments, as above, and skin blood flow was monitored via LDF. Whole body heat stress, sufficient to raise oral temperature at least 0.8°C above baseline, was induced via water-perfused suits. The data obtained from these experiments suggest A[subscript]1/A[subscript]2 adenosine receptor activation does not directly contribute to cutaneous active vasodilation; however, a role for A[subscript]1/A[subscript]2 adenosine receptor activation is unmasked when NO synthase is inhibited. The data from this study further suggest that A[subscript]1/A[subscript]2 adenosine receptor activation may be responsible for a portion of the known NO component of cutaneous active vasodilation.

Master of Science / Department of Kinesiology / Brett J. Wong / Nitrate supplementation in the form of beetroot juice (BRJ) has been shown to increase nitric oxide (NO), where nitrate can be reduced to nitrite and NO through both nitric oxide synthase (NOS) independent and dependent pathways. We tested the hypothesis that BRJ would augment the NO component of cutaneous thermal hyperemia. Dietary intervention consisted of one shot of BRJ for three days. Six subjects were equipped with two microdialysis fibers on the ventral forearm and randomly assigned to lactated Ringer’s (control) or continuous infusion of 20mM L-NAME (NOS inhibitor). The control site was subsequently perfused with L-NAME once a plateau in the local heating response was achieved to quantify NOS-dependent cutaneous vasodilation. Skin blood flow via laser-Doppler flowmetry (LDF) and mean arterial pressure (MAP) were measured; cutaneous vascular conductance (CVC) was calculated as LDF/MAP and normalized to %CVCmax. Maximal vasodilation was achieved via local heating to 43°C and 54mM sodium nitroprusside infusion. There was a significant decrease in DBP after BRJ (Pre-BRJ:74 ± 1 mmHg vs. Post-BRJ: 61 ± 2 mmHg; p < 0.05) and significant reduction in MAP after BRJ (Pre-BRJ: 90 ± 1 mmHg vs. Post-BRJ: 80 ± 2 mmHg; p < 0.05). The initial peak and secondary plateau phase of cutaneous thermal hyperemia were attenuated at sites with continuous LNAME; however, there was no effect of BRJ on either the initial peak at control sites (Pre-BRJ: 76 ± 3%CVCmax vs. Post-BRJ: 75 ± 4%CVCmax) or L-NAME sites (Pre-BRJ: 60 ± 4%CVCmax vs. Post-BRJ: 59 ± 5%CVCmax) or the secondary plateau phaseat control sites (Pre-BRJ: 88 ± 4%CVCmax vs. Post-BRJ: 90 ± 4%CVCmax) or L-NAME sites (Pre-BRJ: 45 ± 5%CVCmax vs. Post-BRJ: 51 ± 3%CVCmax). The decrease in %CVCmax to L-NAME infusion during the plateau of local heating (i.e. post-L-NAME drop) was greater after BRJ (Pre-BRJ: 36 ± 2%CVCmax vs. Post-BRJ: 28 ± 1%CVCmax; p < 0.05). This resulted in a greater contribution of NOS to the plateau phase of local heating (Pre-BRJ: 57±3%CVCmax vs. Post-BRJ: 64±2%CVCmax; p < 0.05). These data suggest BRJ modestly improves NOS-dependent vasodilation to local heating in the cutaneous vasculature of healthy humans.

Doctor of Philosophy / Department of Human Nutrition / Mark D. Haub / Maximizing performance and results in competitive events is something that all athletes strive to achieve. Nutritional strategies have been developed to best optimize the likelihood of success in competitive events. While dietary protein was classically believed to be the key macronutrient in exercise performance, overwhelming evidence now supports the role of maximizing carbohydrate intake and availability in endurance performance. The role of carbohydrate intake prior to, during and after endurance exercise has been heavily studied and relevant literature will be discussed herein. This paper consists of three chapters and a summary related to carbohydrate intake and performance outcomes in endurance sports. While nutritional status surrounding the endurance events is discussed, this paper focuses on the ergogenic and metabolic effects of carbohydrates during the endurance bout. Chapter one serves as a literature review of carbohydrate administration during endurance exercise. Types of carbohydrates, their role as substrates in liver and skeletal muscle during exercise, and their effects on endurance performance are discussed. The role of carbohydrate on central factors of fatigue and motor output also are covered. Chapter two addresses the role of multiple carbohydrate supplements on cycling performance. The role of these supplements on blood glucose, insulin, lactate, and IGFBP-1 also are discussed. Chapter three addresses the effect of nutritional status prior to exercise on the ability of a carbohydrate mouth rinse to impart a performance enhancing effect. There were no treatment effects (p>0.05) of the type carbohydrate ingested, compared with placebo, on selected metabolic and performance outcomes. Likewise, there was no ergogenic effect of mouth rinsing, in the fasted or fed state, in moderately trained endurance cyclists.

Master of Science / Department of Kinesiology / Craig A. Harms / Expiratory flow limitation (EFL) during exercise can limit exercise tolerance. We have recently reported a high prevalence of EFL independent of sex in prepubescent children (Swain et al. 2010) that greatly exceeds that reported in adults. It is unknown how maturation and growth from pre- to post-puberty affects pulmonary function, specifically EFL, during exercise. The purpose of this longitudinal study was to investigate the changes in cardiopulmonary function from pre- to post-puberty in boys and girls. We hypothesized that EFL prevalence would decrease from pre- to post-puberty (with boys exhibiting a greater decrease than girls) and that the decrement could be explained by an increase in pulmonary function and a decrease in VE/VCO2. Twenty-one children (ages 12-16 yrs; 11 boys, 10 girls) were recruited from 40 prepubescent children who completed testing in our laboratory ~5 years ago. Subjects completed pulmonary function tests before and after an incremental exercise test to exhaustion (VO2max) on a cycle ergometer. EFL was determined using the percent tidal volume (VT) overlap method. Nineteen of the 21 subjects (10 boys, 9 girls; 90%) exhibited EFL pre-puberty, while only 7 of the 21 subjects (5 boys, 2 girls; 33%) exhibited EFL post-puberty. Of the subjects who experienced EFL post-puberty, all had experienced EFL pre-puberty. Boys had a significantly greater vital capacity (VC) than girls both pre- (~15%) and post-puberty (B: 4.73 ± 0.53; G: 3.80 ± 0.29 L). Maximal aerobic capacity (VO2max) significantly increased (~110% in girls and ~120% in boys) from pre- to post-puberty and was greater (p<0.05) in boys post-puberty (B: 2.76 ± 0.43; G: 1.94 ± 0.35 L/min). VE/VCO2 also significantly decreased (~13%) in both boys and girls. Post-puberty subjects regulated tidal breathing at higher lung volumes (greater ERV/FVC and lower IRV/FVC) during exercise compared to pre-puberty. None of the subjects experienced significant arterial desaturation pre-puberty or post-puberty. Our findings suggest that the prevalence of EFL declines as children mature from pre- to post-puberty, likely due to increases in lung size, decreases in VE/VCO2, and/or changes in breathing mechanics that are greater than increases in maximal ventilation that occur with increased pulmonary gas exchange.

Master of Science / Department of Kinesiology / Thomas J. Barstow / Purpose: Oxygen uptake (VO2) has been shown to be controlled by a nonlinear system, yet the VO2 response to ramp style exercise appears linear. We tested the hypothesis that an integrative model incorporating nonlinear parameter values could accurately estimate actual VO2 responses to ramp style exercise. Methods: Six healthy, men completed three bouts of varying ramp rate exercise (slow ramp (SR): 15 W/min, regular ramp (RR) 30 W/min, fast ramp (FR) 60W/min) and four bouts of extended-step incremental exercise, where each step lasted 5-15 min or until volitional fatigue on a cycle ergometer on separate days. The step-responses were then fit with a simple monoexponential starting at time zero (MONO) or allowing a time delay and using only the first 5 min of data (5TD). The resulting VO2 parameters from the step protocol were incorporated into an integrative model for the estimation of the VO2 response to each of the rates of ramp incremental exercise. The parameters from the actual and model ramp protocols were compared with 2 way repeated-measures ANOVAs. Results: Both Gain (G) and Mean Response Time (MRT) (or time constant) values increased significantly across work rate transitions (mean±SD; Gain:10.0±0.9, 11.6±1.1, 13.1±1.3, 17.6±3.3 ml O2/min/W; MRT:39.4±7.7, 54.0±5.4, 79.6±15.0, 180.1±56.2 s). Up to maximalVO2 the models over-estimated the actual VO2 response for FR (Gain: ACT 8.7±1.0, MONO 9.9±0.4, 5TD 10.3±0.3 ml O2/min/W). Up to 80% maximal VO2 the models accurately predicted the actual VO2 response across all ramp rates (Gain: ACT 10.7±1.1, 10.2±0.5, 9.2±1.0; MONO 11.0±0.8, 10.3±0.6, 9.2±0.5; 5TD 10.4±0.4, 10.2±0.3, 9.8±0.2 ml O2/min/W, values are listed SR,RR,FR). Conclusions: When variable parameter values (G and either MRT or time constant and time delay) were utilized by an integrative model, accurate estimations of the VO2 response to ramp incremental exercise were possible regardless of ramp rate (up to 80% maximal VO2). The increases in both G and MRT (or time constant) appear to balance each other to produce the quasi-linear VO2 responses.

Master of Science / Department of Kinesiology / Katie Heinrich / Background: The American College of Sports Medicine physical activity guidelines call for 150 minutes of moderate or 75 minutes of vigorous aerobic exercise plus two days of resistance training (A-RT) per week for health benefits. Yet, most adults do not achieve the recommended amount of physical activity per week frequently citing lack of time as a barrier. High-intensity exercise protocols have improved glucose control, insulin sensitivity, fitness, and body composition, in less total time than lower intensity protocols, but have been studied as singular modes of exercise. CrossFit (CF) temporally combines A-RT together utilizing constantly varied multi-joint, full range-of-motion movements in substantially less training time than lower-intensity protocols. The aim of this study was to compare the effects of CF versus A-RT on glucose control in overweight/obese, physically inactive individuals. Methods: Eighteen overweight/obese (BMI 30.3 ± 2.8) adults (28.5 ± 5.9 years) were randomized to one of two groups: CF (3 days/week for 60 minute sessions) or A-RT (3 days/week of aerobic exercise for 50 minutes, plus ~20 minutes resistance exercise on 2 of those days) over 8-weeks. Fasting plasma glucose and 1-hour oral glucose tolerance tests were taken at baseline and post-training along with Eurofit fitness measures, VO2 peak, and body composition via dual energy X-ray absorptiometry. Results: Glucose control and body composition did not change significantly within or between groups. Both groups significantly improved muscular endurance (pushups completed on knees, CF+39.5%, p < 0.05; A-RT+24.4%, p = 0.01). The CF group improved on number of situps (CF+6.8%, p = 0.01) and VO2 peak (CF+9.1%, p < 0.05). Time spent exercising was significantly different between groups with the CF group averaging 38.7 ± 15.6 minutes per week and 13.1 ± 0.9 minutes per workout, and the A-RT group averaging 190.0 ± 10.7 minutes per week and 63.3 ± 3.6 minutes per workout. Conclusion: Eight weeks of A-RT or CF did not produce significant changes in glucose control or body composition in overweight/obese adults. However, despite exercising significantly less time per week CF training demonstrated greater improvements in fitness measures than A-RT.

Master of Public Health / Department of Kinesiology / Katie M. Heinrich / Background and Purpose: Trails can help increase community physical activity levels but little is known about the role that collaborations play in building a trail. Social network analysis may be a useful tool to examine collaborations among various stakeholders, such as municipal public works, parks and recreation, community organizations, hospitals, local businesses, universities, and schools. The purpose of this project is threefold: a) to identify the number and type of organizations involved in trail building, b) to examine the centrality and density of social networks in the trail building process and c) to determine whether collaborations differ between the three phases of trail building (generation, grant funding and construction). Methods: Thirty-four successful trail project builders funded by the Sunflower Foundation of Kansas participated in an online survey designed to explore collaborations throughout the trail building process. Social network analysis adapted from procedures developed by Wickizer and colleagues (1993) was used to identify key organizations in building trails, to estimate the overall density and centrality of connections between the organizations, and to determine differences in collaborations by project phase. Results: Fifteen different groups (e.g. non-profit community organizations, city parks and recreation department, city public works, schools) were identified as part of the trail building process. Non-profit community organizations were most central to trail building during all three phases (generation (.36) grant writing (.38), and construction (.41)). All three phases of trail building were only weakly connected as indicated by density of social network scores measured during the generation (5.7%), grant writing (6.2%) and construction phases (7.5%). Centrality of social networks was high for all three phases of the trail building process, the generation phase (0.32) the grant writing phase (0.27) and the construction phase (0.36). Conclusions: This exploratory analysis suggests Social Network Analysis may be a useful tool to study organizations that collaborate to build trails for physical activity. During the distinct phases of trail-building, the role of collaborations changed. Some organizations were more important in the planning phase, grant writing or construction, while others (e.g. non-profit community organizations) were important throughout the entire process. Additionally, the density of social network increased as the trail projects progressed. The relationships between organizations were often weak but provided a flow of necessary information and skills to successfully build a trail. Future research should attempt to understand these time-dependent collaborations and encourage them in future trail and other built environment projects that support physical activity.

Master of Science / Department of Kinesiology / Timothy I. Musch / Impaired vasomotor control in chronic heart failure (CHF) limits the delivery of O[subscript]2 to skeletal muscle during exercise. Previous results demonstrate significant increases in skeletal muscle blood flow (BF) during exercise with omega-3 polyunsaturated fatty acid (PUFA) supplementation via fish oil (FO) versus safflower oil (SO) in healthy rats (Stebbins CL et al., Int J Sport Nutr Exerc Metab 20:475-86, 2010). Whether PUFA supplementation with FO will improve vasomotor control in CHF and skeletal muscle BF during exercise remains to be determined. This investigation tested the hypothesis that PUFA supplementation with FO would augment the skeletal muscle BF response to exercise in rats with CHF when compared to SO. CHF was induced in male Sprague-Dawley rats by myocardial infarction produced via left coronary artery ligation. Rats were then randomized to dietary FO (20% docosahexaenoic acid and 30% eicosapentaenoic acid, n = 8) or SO (5% safflower, n = 6) supplementation for 6 weeks. Rats remained on their respective diets until final experiments were conducted. Following acute instrumentation and recovery (> 1 hour), mean arterial pressure (MAP), skeletal muscle BF to the total hindlimb and individual muscles (via radiolabeled microspheres), and blood lactate concentration were determined during rest, submaximal treadmill exercise and exercise+LNAME (20 m · min[superscript]-[superscript]1, 5% incline). Left ventricular end-diastolic pressure (LVEDP) measured in the SO and FO groups during instrumentation were similar and demonstrated moderate CHF (LVEDP; SO: 14 ± 2; FO: 11 ± 1 mmHg, P>0.05). During submaximal exercise, MAP (SO: 128 ± 3; FO: 132 ± 3 mmHg) and blood lactate (SO: 3.8 ± 0.4; FO: 4.6 ± 0.5 mmol · l[superscript]-[superscript]1) were similar (P>0.05) between groups. Exercising hindlimb skeletal muscle BF was higher in SO compared to FO (SO: 120 ± 11; FO: 93 ± 4 ml · min[superscript]-[superscript]1 · 100 g[superscript]-[superscript]1). Specifically, 17 of 28 individual hindlimb muscle BF’s were higher (P<0.05) in SO. These data suggest that PUFA supplementation with FO in rats with moderate CHF decreases the skeletal muscle BF response to submaximal whole body exercise.

Master of Science / Department of Kinesiology / Craig A. Harms / Obesity and asthma often coexist in the same people. Both are characterized by the presence of low-grade systemic inflammation. A high-fat diet may contribute to concurrent development of both conditions by promoting a pro-inflammatory postprandial environment leading to a transient accumulation of blood lipids (postprandial lipemia; PPL) and acute airway inflammation. Previous results from our lab have shown an ~20% increase in airway inflammation two hours after consuming a high-fat meal (HFM) that was significantly associated with increased plasma triglycerides. While acute exercise has been shown to attenuate PPL, it is unknown whether these protective effects will translate to reduced airway inflammation after a high-fat meal. PURPOSE: To determine the effects of an acute bout of exercise on airway inflammation after a HFM. We tested the hypothesis that an acute bout of exercise 12 hours before a high-fat meal would protect against subsequent airway inflammation in healthy men and would be related to the decreased PPL and systemic inflammatory markers. METHODS: In a randomized cross-over study, 12 healthy college-aged men consumed a HFM (1g fat/1kg body weight) 12 hours following exercise (EX; 60 min at 60% VO2max) or without exercise (CON). Exhaled nitric oxide (eNO; measure of airway inflammation), blood lipid profiles (venous sample; total cholesterol, HDL, LDL, triglycerides, glucose), inflammatory markers (hsCRP, TNF-[alpha], IL-6) and pulmonary function tests (PFT) (forced expiratory volume in 1-s,forced vital capacity, forced expiratory flow at 25-75% of vital capacity) were measured pre-HFM, two hours, and four hours post-HFM. RESULTS: Baseline eNO was not different (p>0.05) between trials. eNO increased (p<0.05) post HFM at two hours in the both CON and EX conditions. eNO between trials was not different (p>0.05). Triglycerides were significantly increased two and four hours post HFM but were not different (p>0.05) between conditions. There was no relationship (p>0.05) between eNO and triglycerides or systemic inflammatory markers for any time point in either condition. Pulmonary function did not differ (p>0.05) between any condition. CONCLUSION: These results demonstrate that an acute bout of moderate intensity exercise 12 hours before a HFM does not attenuate postprandial airway inflammation or lipemia in healthy college-aged men.