Theses and Dissertations at Montana State University (MSU)
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Item The influence of lower body compression clothing on markers of running economy during submaximal treadmill running(Montana State University - Bozeman, College of Education, Health & Human Development, 2011) Bakken, Bjorn; Chairperson, Graduate Committee: Daniel P. HeilThe benefit of wearing lower-body compression clothing for individuals experiencing circulatory disorders has been well documented, yet little is known about benefits of wearing such clothing during endurance exercise. This was an investigation of the influence of lower-body compression clothing (stockings and shorts) on markers of running economy. METHODS: Eleven endurance runners (Mean±SD: 33±7 yrs, 67.9±15.5 kg) completed treadmill tests on three separate lab visits. First, subjects performed a running test to volitional exhaustion to measure maximal oxygen uptake (VO 2MAX) and heart rate at lactate threshold (HR LT). During the next visit, subjects ran for 90-mins at a speed that elicited 85% of HR LT (Mean±SD: 6.9±0.6 miles/hr for men and 6.7±0.5 miles/hr for women) while wearing one of two lower-body clothing conditions: compression shorts and stockings or running shorts. Subjects ran 90-mins again for the last visit at the same speed wearing the second clothing condition, the order of which was counterbalanced. During the 90-min runs, measures of oxygen uptake (VO 2), heart rate (HR), left-thigh accelerometry (AC), and blood pressure (BP) were summarized at the sixth minute of each successive 10-min time interval (T1-T9). Blood lactate (LA) was measured at the end of each time interval. Blood samples were also collected pre- and 24-hrs post-test to measure blood creatine-kinase (CK), an indicator of muscle damage. Values of VO 2 and HR were also summarized as the change for each subject from their T1 values (DeltaVO 2 and DeltaHR, respectively). Dependent variables were evaluated using a multivariate 2-factor repeated measures ANOVA with planned contrasts for post-hoc analyses. Comparisons were performed at the 0.05 alpha-level. RESULTS: Measures of VO 2, HR, BP, DeltaVO 2, DeltaHR, and CK were statistically similar at each time interval between conditions (P>0.05). Conversely, AC was significantly lower when wearing compression clothing during all time intervals (P<0.05). Measures of LA were significantly higher at T6 when wearing compression clothing (P<0.05). CONCLUSIONS: While wearing compression clothing, subjects experienced less movement of the thigh musculature (i.e., less AC), but no improvements in economy (i.e., lower VO 2 or DeltaVO 2) were observed. These results do not indicate any advantage to wearing lower-body compression clothing during endurance exercise.Item The influence of bout interruptions on measured and predicted physical activity during treadmill walking and running(Montana State University - Bozeman, College of Education, Health & Human Development, 2008) Howe, Stephanie Marie; Chairperson, Graduate Committee: Daniel P. HeilThe importance of daily physical activity (PA) has been established as a means of decreasing risk for chronic diseases. However, the presence of bout interruptions ((BI), defined as a brief pause (< 2 min) PA), can complicate measures of PA. This study was designed to evaluate the influence of different BI rules on PA during treadmill locomotion. Fifteen runners (6 women, 9 men) completed a series of walking (53.6, 107.2 m/min) and running (160.8 m/min) trials while using a metabolic measurement system to measure actual activity energy expenditure (AEEA) and four activity monitors to measure predicted AEE (AEEP). Treadmill speeds were selected to elicit light (L), moderate (M), and vigorous (V) PA intensities. Both AEEA and AEEP, were calculated as the sum within and between the start and end of each defined trial using 3 BI rules: 1) without an allowance for a BI (BI0), 2) or a 1-min BI allowance (BI1), 3) or a 2-min BI allowance (BI2). TA and TP were defined as the time spent at or above a moderate intensity during each PA bout for BI0, BI1, and BI2. Values of AEEA and AEEP for each BI definition and PA intensity were compared within intensities categories using a 2-factor RMANOVA, while data for all three PA intensities were evaluated simultaneously using a RMANOVA. Similarly, values of TA and TP for each BI definition were compared using the same multivariate RMANOVA model. Mean AEEA and AEEP for BI0 were significantly lower than those for BI1 and for BI2 at all PA intensities (p<0.05). When expressed as a percentage, the increase in AEEA and AEEP between BI0 and BI1, or BI1 and BI2, was 0.3-3.9% and between 5.5-11.0% for TA and TP across all intensities. Allowing for 1- or 2-min BIs within a PA bout significantly influences AEE and time during locomotion. These results suggest that rules for the number of BIs allowed should be established since an increase in BIs will cause PA outcome variables to become more dependent on the BIs than the PA itself.