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Autonomic Nervous System Response to Repeated Cold ExposureSimmons, Jonathan A 17 October 2013 (has links)
Recent work suggests repeated cold exposure raises energy expenditure, partly due to sympathetic nervous system stimulation, which indicates repeated cold exposure as a possible strategy to combat obesity without significant behavioral changes.
PURPOSE: (1) To examine the acute resting metabolic rate (RMR) response to mild cold exposure of 16° C and the acute autonomic nervous system (ANS) response to two cold exposures of 16° C and 4° C through heart rate variability (HRV) indices; and (2) to examine whether 4 weeks of daily cold exposure would result in adaptations in the metabolic and autonomic responses to acute cold exposure.
METHODS: RMR and HRV measurements were used to measure acute cold exposure response at 22° C and prolonged cold exposure response after 90 minutes at 16° C. HRV measurements were also used for acute exposure at 22° C and continuously during 20 minutes of cold exposure at 4° C. RMR and ANS responses to 16° C following 20 sessions (400 minutes) of repeated cold exposure were measured. RMR was measured using a metabolic cart and ANS activity was examined through the measurement of HRV.
RESULTS: A significant increase in RMR of 11% (p=0.03) and an increase in Total Power that approached significance (p=0.07) was measured after 90 minutes of exposure to 16° C. Upon exposure to 4° C, significant (p<0.05) increases in Total Power, High Frequency, and RMSSD indices of HRV were measured with Low Frequency approaching significance (p=0.07). No significant findings were measured after repeated cold exposure in comparison to baseline measurements.
CONCLUSION: Acute cold exposure of 16° C resulted in a significant increase in RMR of 11% with increased activation of the autonomic nervous system measured at both 16° C and 4° C. Twenty sessions of repeated cold exposure of 4° C did not significantly alter acute responses to cold exposure. There was no evidence of a change in autonomic balance toward a hyper-adrenergic state due to cold exposure. These findings suggest repeated cold exposure may be an effective tool for significantly increasing metabolic rate without changing autonomic balance toward a hyper-adrenergic state.
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Perceptions of the Motivational Climate and Gender Class Structure in Physical EducationDelgado, Lauren E 15 November 2013 (has links)
Many children do not engage in the recommended levels of physical activity, and they ten to become even less active during adolescence. Girls are less active then boys, and it is important to explore ways that physical education teachers can foster girls motivation to be more physically active. The specific research questions for this study were: (a) How does gender class structure affect girls perception of the motivational climate?; and (b) How do girls views of the motivation climate in different gender class structures relate to intentions to participate in physical activity outside of physical education? A phenomenological framework guided the data collection and analysis when comparing and contrasting girls perceptions of the motivational climate in single-sex and coeducational physical education classes. Two secondary physical education classes were observed one in an all-female setting and the other in a coeducational setting. Students were observed in their physical education classes and through emergent sampling fifteen students were chosen to interview. Findings illustrate that a teachers personal qualities and teaching behaviors can have an effect on adolescent female motivation. Perception of the social environment was also an influencing factor on females motivation level, including perception of relatedness, gender structure, and comfort level. The findings show that when students source of comparison was internal, they were more likely have an outside interest in an activity, enjoy physical education, state that they were likely to participate in physical activity outside of physical education, and find utility in an activity. These results highlight the importance of physical educators providing a positive environment through feedback and encouragement for adolescent females. They also show that adolescent female comfort levels can be threatened when participating in a coeducational setting. Finally, in order to cultivate high motivational levels in adolescent females, goals established within physical education classes should be focused on internal rather than external goals.
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Oxygen Consumption During Exercise: The Role of Venous OcclusionSaltzman, Tiffany Noel 02 December 2013 (has links)
Abstract
Oxygen consumption during exercise is typically used to advance performance, determine fitness level, and make clinical diagnoses. The rate at which VO2 adjusts to and recovers from (i.e. on- and off- kinetics) a bout of exercise is typically associated with certain metabolic processes such as stores of PCr, ATP, replenishing myoglobin, hemoglobin, and removing metabolic waste. The ability of an individual to utilize these processes can determine the speed at which oxygen consumption rises and falls, and thus is associated with the health of the individual (i.e. faster=fitter; slower=unhealthy). The use of circulatory occlusion training has recently become a well-known training technique that allows individuals who cannot exercise at a high intensity to gain physiological adaptations through exercise at a low intensity.
The current study used venous occlusion in an acute bout of exercise to determine whether venous function has an effect on oxygen consumption kinetics. Twelve subjects exercised at 60% of VO2 max for 6 minutes on two separate occasions. One condition was considered non-occluded (NON), the other was occluded (OCC); OCC condition consisted of 40mmHg of pressure applied to the legs via pressure cuffs. Subjects VO2, heart rate, and RER were recorded during exercise and 6 minutes prior and 6 minutes following exercise. All variables were assessed as area under the curve (AUC) 6 minutes prior (pre), during on transition (on-kinetics), during 6 minutes of exercise (exercise), and 6 minutes following (off-kinetics). No statistically significant differences existed in AUC between conditions for on- (VO2; NON: 6024.97± 1117.56, OCC: 5971.26± 1398.15, HR; NON: 35875± 7713, OCC: 36634± 6379, RER; NON: 246.63± 46.21, OCC: 253.76± 48.78) or off-kinetics (VO2; NON: 5744.40± 1233.59, OCC: 5913.88± 1498.91, HR; NON: 62672± 22, OCC: 63469± 20, RER; NON: 640.0976± 146.53, OCC: 672.0076± 156.33). Furthermore, shortening the time periods analyzed also showed no significant difference for all variables. It is evident that these individuals were able to buffer the accumulation of metabolites that occurs with occlusion during an acute bout.
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A Multi-theoretical Analysis of Motivation in College Activity CoursesHines, Louis 06 April 2015 (has links)
College activity courses present an opportunity for physical educators to increase physical activity among young adults. Facilitating motivation in activity courses may lead to increased engagement and future participation in physical activities. The purpose of this study was to examine motivation in college activity courses utilizing a multi-theoretical approach in order to assess changes in physical self-concept and intention for participation in physical activities. It was hypothesized that a task-involved motivational climate would predict need satisfaction, which would in turn predict self-determined motivation. It was further hypothesized that this motivational sequence would predict changes in physical self-concept and intention to engage in physical activity.
Participants were 370 college students (300 female, 70 male; M= 20.4±1.3 years) enrolled in physical activity classes at a large university in the Southeastern United States. They completed questionnaires assessing physical self-concept and intention at the beginning of the semester. At the end of the semester, participants completed questionnaires assessing physical self-concept, intention, perceptions of the motivational climate, basic psychological need satisfaction, and self-determined motivation.
Path analysis and bivariate correlations were used to analyze the relationships among variables. Residual gain scores were calculated for physical self-concept and intention as a measure of change over time (Prochaska, Velicer, Nigg, & Prochaska, 2008). In path analysis, the hypothesized model represented a good fit for the data (S-B . χ² (8) 5.72, p= .68; CFI= .99; RMSEA= .01; SRMR= .026). The motivational sequence represented by the model predicted changes in physical self concept, but not intention. The modification index indicated that a direct path between basic psychological need satisfaction and intention would improve the hypothesized model (Beta= .33; p< .01). A task-involved climate had a significant indirect effect on self-determined motivation and changes in intention. An ego-involved climate had a negative relationship with basic psychological need satisfaction, self-determined motivation, and intention.
Results of this study highlight the importance of facilitating a task-involved climate that satisfies basic psychological needs in order to elicit positive changes in physical self-concept and intention to participate in physical activities among young adults enrolled in college activity courses.
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The Influence of the Lower Trapezius Muscle on Shoulder Impingement and Scapula DyskinesisCoulon, Christian Louque 26 March 2015 (has links)
This dissertation contains three experiments all conducted in an outpatient physical therapy setting. Shoulder impingement is a common problem seen in overhead athletes and other individuals and associated changes in muscle activity, biomechanics, and movement patterns have been observed in this condition. Differentially diagnosing impingement and specifically addressing the underlying causes is a vital component of any rehabilitation program and can facilitate the individuals return to normal function and daily living. Current rehabilitation attempts to facilitate healing while promoting proper movement patterns through therapeutic exercise and understanding each shoulder muscles contribution is vitally important to treatment of individuals with shoulder impingement. This dissertation consisted of two studies designed to understand how active the lower trapezius muscle will be during common rehabilitation exercises and the effect lower trapezius fatigue will have on scapula dyskinesis. Study one consisted of two phases and examined muscle activity in healthy individuals and individuals diagnosed with shoulder impingement. Muscle activity was recorded using an electromyographic (EMG) machine during 7 commonly used rehabilitation exercises performed in 3 different postures. EMG activity of the lower trapezius was recorded and analyzed to determine which rehabilitation exercise elicited the highest muscle activity and if a change in posture caused a change in EMG activity. The second study took the exercise with the highest EMG activity of the lower trapezius (prone horizontal abduction at 130¢ª) and attempted to compare a fatiguing resistance protocol and a stretching protocol and see if fatigue would elicit scapula dyskinesis. In this study, individuals who underwent the fatiguing protocol exhibited scapula dyskinesis while the stretching group had no change in scapula motion. Also of note, both groups exhibited a decrease in force production due to the treatment. The scapula dyskinesis in the fatiguing group implies that lower trapezius function is vitally important to maintain proper scapula movement patterns and fatigue of this muscle can contribute and even cause scapula dyskinesis. This abnormal scapula motions can cause or increase the risk of injury in overhead throwing. This dissertation provides novel insight about EMG activation during specific therapeutic exercises and the importance of lower trap function to proper biomechanics of the scapula.
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Recovery from Exercise: The Influences of Supplementation and Rest IntervalMiskowiec, Ryan 27 April 2015 (has links)
Recovery from exercise is immensely important and under studied. The experiments conducted throughout this research have focused on testing the effects of rest interval during resistance exercise and the efficacy of acetic acid feeding on recovery rate. To elucidate the relationship between rest interval and recovery energy expenditure two experiments were undertaken. These experiments were designed to alter only rest interval while maintaining work intensity and volume. No difference in the total energy expenditure during the short phase of recovery (first hour) was found, but energy expenditure during the prolonged phase (days post exercise) was minorly increased by lowering rest interval. These results combined with the metabolic and affective data collected have raised questions as to the underlying mechanisms which warrant further study. The third and fourth experiment focused on acetic acid consumption and recovery from exhaustive exercise. Previous studies in animal models have shown significantly improved recovery rates. This research was focused on testing the efficacy of acetic acid feeding in humans to improve performance. Participants therefore exercised, were given a time to rest, and a recovery beverage was consumed. After recovery participants ability to perform was assessed, and various metabolic measurements were assessed. The findings of these projects are promising, as acetic acid appears to have positive effects on recovery. The potential benefits to millions of athletes in a variety of sports are immense. The work completed throughout this Dissertation has successfully added to the field of recovery research, and provided more questions to be answered in the future.
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Motor Learning Effects of Two Types of Stressors: Implications for Practice SpecificityAiken, Christopher Adam 01 July 2015 (has links)
Various types of stress have been found to have both positive and negative effects on motor performance (Szalma & Hancock, 2011; Van Gemmert & Van Galen, 1997). One potential explanation for these diverse findings is that stress increases the amount of neuromotor noise in the system (Van Gemmert, 1997). Low levels of stress may have an activating effect on the system which may improve motor performance whereas larger levels of stress decrease motor performance. Research has also suggested that increases in stress increase effort (Hockey, 1997) which may in turn facilitate motor learning (Lee, Swinnen, & Serrien, 1994). The primary purpose of this dissertation was to examine potential effects of cognitive and physical stress on motor learning. Chapter 1 provides some background information on stress and it also introduces some theories developed to explain the relationship between stress and human motor performance. Chapter 2 describes a study on the potential effects of cognitive stress on motor learning. It was found that additional cognitive stress hindered motor performance (p < .001) but did not impede motor learning of a timed aiming task when the cognitive stressor was removed (p > .05). The second experiment (chapter 3) is about the effects of physical stress (80dBs of continuous white noise) on motor learning. Results revealed that increased physical noise negatively affected reaction time (p < .05) on a timed aiming task but did not affect other performance measures (p > .05). During a no stress transfer test the group that practiced with the increased physical stress had marginally longer reaction times (p = .06). In chapter 4 a study about specificity of practice and stress (cognitive and physical) is presented. In this chapter stress was added during a transfer test to see if learning was specific to the environment (stress or no stress) during practice. The addition of cognitive stress during transfer significantly diminished motor performance (p < .001), but the addition of physical stress seemed not to affect motor performance (p > .05). Chapter 5 provides discussion on the results from the three experiments. The results are discussed in the context of practice specificity and the neuromotor noise theory.
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An Experimental Investigation of Autonomy Support Versus Thwart in an Exergaming ContextWeathers-Meyer, Amanda Joy 16 July 2015 (has links)
Considerable literature in self-determination theory (SDT) establishes satisfaction of basic psychological needs related to competence, autonomy, and relatedness as important determinants of well-being and motivation. Despite the abundance of SDT literature, few studies provide an investigation of autonomy support and autonomy thwart within an experimental design. Using SDT as a guiding framework, the effects of autonomy support (AS) versus autonomy thwart (AT) were examined within an exergaming context. Specifically, this study investigated the impact of autonomy support / thwart on five variables: perceived autonomy need satisfaction and autonomy thwart, affect, game performance, and willingness to recommend the study to others. Students (N = 75) aged 18 to 25 years participated in lab sessions assessing study variables. One-way and factorial ANOVAs revealed that (a) participants in the AS condition reported higher levels of autonomy support and lower levels of autonomy thwart than the control and AT condition, (b) students in the AT group reported higher levels of autonomy thwart and lower levels of autonomy support than the control or AS condition, (c) AT students indicated greater negative affect from baseline to post-test compared to the AS and control participants, and (d) AS and control participants reported an increase in positive affect while the AT group demonstrated a slight decline in positive affect that was not significant. Results align with previous SDT research regarding social-contextual environments. Furthermore, findings suggest that leaders within a learning environment should consider pedagogical choices and contextual manipulations that elicit AS in order to promote optimal functioning from the subjects in their care.
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An Investigation of the Quality and Quantity of Student Motivation in Physical EducationWilloughby, Trey Douglas 20 July 2015 (has links)
Physical inactivity is a prevalent problem in the United States associated with numerous health risk factors. Over half the population fails to meet prescribed physical activity recommendations, suggesting that individuals become less active as they age. It is important to observe individuals in the Physical Education setting because it is an ideal environment to provide meaningful physical activity, while promoting lifetime physical activity. This research sought to understand motivational behaviors in high school adolescents, attempting to draw links between physical education, student satisfaction, and leisure-time physical activity. Three research questions were present: (1) What relationships do high school student perceive among the motivational climate, basic psychological need satisfaction, and the quality and quantity of motivation? (2) What does quantity of motivation and quality of motivation in PE add to the understanding of student satisfaction in PE? and (3) Is there a trans-contextual relationship between the quality and quantity of motivation in PE and leisure-time physical activity? The study was grounded in self-determination theory and achievement goal theory, while adding a quantity of motivation variable, a degree of motivational strength. Two secondary schools were observed, an all-male school and an all-female school, with cross-sectional analysis through questionnaires. Hierarchical multiple linear regression models sough to predict quality and quantity of motivation from perceptions of motivational climate and basic need satisfaction. Also, quality and quantity of motivation, including an interaction term, was used to predict domains of student satisfaction. Initial findings suggested that perceptions of mastery climates, competence and relatedness need support were significant predictors of quantity and quality of motivation. Quality of motivation was a significant predictor of social, emotional, and fitness satisfaction in PE students, while quantity of motivation significantly predicted emotional and fitness satisfaction. The interaction term suggested that motivation quantity raised emotional satisfaction in students with low to average RAI levels with no variability at high RAI levels. These results suggest the importance of motivational quantity on various forms of satisfaction. Its inclusion in future research may discover more links between PE and motivational behavior, ultimately promoting more physical activity.
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The Anti-Inflammatory Effects of Vitamin D and ExerciseForney, Laura Ann 11 November 2014 (has links)
Elevated inflammation is associated with several chronic diseases, including obesity. Exercise is an established effective treatment of this condition by decreasing adiposity and independently regulating inflammatory pathways. The potential for vitamin D to confer anti-inflammatory benefits has been explored in cell culture studies, but few have explored its action at the whole body level. PURPOSE: To investigate the relationship between inflammatory markers in trained and untrained individuals with vitamin D levels either above or below a suggested optimal concentration. METHODS: College-aged females (N = 63), both trained and untrained, reported to the lab four times: to assess body size and composition, for blood collection, for a maximal aerobic test, and a test of anaerobic power. Blood was analyzed for serum 25OHD and CRP concentrations, stimulated with LPS to assess IL-6 production. Samples were prepared for FACS analysis for CD14, CD16, and TLR4 expression. RESULTS: Trained individuals presented with higher 25OHD levels, even prior to stratification into high and low groups (p = 0.015). VO2peak was significantly higher (p < 0.0001) and fatigue during the test for anaerobic power was significantly lower (p = 0.021) in trained individuals. Untrained individuals had a higher average body weight (p = 0.039) and estimated percent body fat (p = 0.011) compared to trained individuals, although the average estimated percent body fat of both groups was higher than the recommended level for this age group. Additionally, measures of sun exposure were negatively correlated with measures of body size and composition, although these relationships did not exist between serum 25OHD. CONCLUSION: In this study, regular physical activity was associated with higher serum 25OHD, lower BMI, waist circumference, and estimated percent body fat as well as reduced LPS-stimulated IL-6 production. Optimal vitamin D status did not appear to provide any additional health related or anti-inflammatory benefit in those with regular physical activity habits. However, in individuals not participating in a regular exercise program, the potential for vitamin D to mediate inflammation appeared more likely. More specifically, untrained people with optimal vitamin D status had lower numbers of total monocytes, CD14+CD16- cells, and decreased TLR4 expression on CD14+CD16+ cells; however, these differences did not translate into a change in overall cell function or markers of systemic inflammation as there was no difference between optimal and suboptimal groups with respect to LPS-stimulated IL-6 production or resting CRP concentrations. An expanded exploration of the relationship between vitamin D and inflammation may include assessing other inflammatory biomarkers, immune cell types, the vitamin D receptor, and the role of adipose tissue.
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