In recent studies, caloric intakes among female distance runners were reported to be insufficient to support training intensities. To study energy intake and expenditure in female collegiate distance runners, ten members of the Virginia Tech cross-country team were utilized as subjects. / Master of Science

published_or_final_version / Sports Science / Master / Master of Science in Sports Science

Call number: LD2668 .T4 1985 W54 / Master of Science

Thesis (M.Tech.: Chiropractic)-Dept. of Chiropractic, Durban University of Technology, 2007. xii, 72, 12 leaves / Aims and Objectives: The aim of this study was to determine whether spinal manipulation affects the perceived performance of runners with low back pain. More specifically, the objective was to determine whether any relationships existed between spinal manipulation, a runner’s perceived performance and their low back pain. Method: Twenty subjects who ran thirty kilometers a week and had LBP were selected for a pre- post- cohort study according to criteria set out beforehand. The subjects received spinal manipulation applied to their lower back twice a week for a period of two weeks. At each consultation, they were requested to fill out a “Perception of Running Performance” questionnaire prior to each treatment, and one week following the final consultation.

The purpose of this study was to examine the effects of a 4-week reduction in training volume and intensity on performance of distance runners. Ten well-conditioned males underwent 4-weeks of base training (BT) at their accustomed training distance (71.8 ± 3.6 km/wk) and pace (76% of total distance above 70% V02 max intensity), before reducing training (RT) for an additional 4 weeks. Training volume was decreased by -.66% to 24.8 km/wk and frequency by 50% to 3 runs per week. Training intensity was reduced such that all running was at less than 70% V02 max (68.2 ± 1.6%). At the end of BT (week 0), and weeks 2 and 4 of RT, resting heart rate, calculated plasma volume, testosterone and cortisol levels, and submaximal treadmill efficiency were assessed. At weeks 0 and 4, V02 max and 5 kilometer race performance was determined. The ratio of testosterone to cortisol was increased significantly with RT (0.054 ± 0.008 at week 0 to 0.082 ± 0.020 at week 4), although the individual testosterone and cortisol concentrations were not significantly altered. Maximum oxygen consumption, and time to exhaustion during the max tests were not altered with RT. Body weight tended to increase (p=0.09) due to a significant increase in percent body fat (p<0.05). Submaximal treadmill runs at 65%, 85%, and 95% V02 max revealed no alterations in absolute V02 while relative V02 decreased significantly. This decrease in relative V02 was due partially to the weight increases and partially to a significant increase in respiratory exchange ratio (RER). Resting and submaximal treadmill heart rate (HR) were unchanged with FIT, while maximal treadmill HR and race HR were increased significantly. Calculated plasma volume was unaltered. Leg and overall ratings of perceived exertion were decreased during RT with the overall rating reaching significance (p<0.05). Blood lactic acid concentration was found to be significantly higher at the 95% V02 max workload following RT (8.39 ± 0.46 vs 9.89 ± 0.46 mmol/L at week 0 and 4, respectively). Five kilometer race time increased significantly from 16.6 ± 0.3 at week 0 to 16.8 ± 0.3 minutes at week 4 (12.1 seconds). It is concluded that a 4-week reduction in training volume and intensity in these runners resulted in a significant decrease in race performance despite the maintenance of aerobic capacity. / School of Physical Education

Partial Dissertation in compliance with the requirements for the Master's Degree in Technology: Chiropractic, Durban University of Technology, 2007. / Aims and Objectives: The aim of this study was to determine whether spinal manipulation affects the perceived performance of runners with low back pain. More specifically, the objective was to determine whether any relationships existed between spinal manipulation, a runner’s perceived performance and their low back pain. Method: Twenty subjects who ran thirty kilometers a week and had LBP were selected for a pre- post- cohort study according to criteria set out beforehand. The subjects received spinal manipulation applied to their lower back twice a week for a period of two weeks. At each consultation, they were requested to fill out a “Perception of Running Performance” questionnaire prior to each treatment, and one week following the final consultation. / M

Eighteen subjects each performed fifty-five trials which consisted of assuming an initial stance and then in response to a visual stimulus running to either the left or right. For each trial both the foot width spacing and orientation of the feet were varied. Direct and indirect measurements were taken of selected temporal and kinematic parameters. The conclusions were that no interactions or differences exist among foot width spacing, foot orientation, and direction of movement; the jab step start is the preferred initial movement; the preferred foot width spacing is 46.6 centimeters; the preferred angular orientation of both feet is approximately 1.36 radians.

No description available.

A comparison of heart rate viability and respiratory sinus arrhythmia (RSA) characteristics was performed in 20 athletes and 12 age-matched sedentary controls (CTRL) (22 +/- 2.4 yrs). More specifically, this study examined the role of regular physical activity on the breathing frequency (BF)---RSA amplitude response curve comparing varsity swimmers (SW) to endurance runners (RU) to test the hypothesis that a locomotor-respiratory entrainment resulting from the water-immersion breathing pattern of swimmers would alter their respiratory related cardiac vagal integrative response. Spectral power components of HRV were computed from R-R interval sequences. Five-minute recordings were performed with subjects breathing either at their spontaneous breathing rate, at four breathing cycles less (M4) and four cycles more (P4) than spontaneous. Amplitude and phase of RSA were computed from the sinusoid fitted to the instantaneous heart rate within each breath while the gain of the RSA response was obtained from the slope of the RSA amplitude versus BF. (Abstract shortened by UMI.)

The purpose of this investigation was to examine the contractile properties of individual slow and fast myofibers in response to various training periods throughout a collegiate cross-country season in male runners. Muscle biopsies were obtained from the gastrocnemius of five runners at three time points during the season; after a summer aerobic training phase (T1); after an 8 week period of intense training (T2) and after a 4 week taper period (T3). Absolute (4.6±0.3 L/min) and relative (71±0.7 mI/kg/min) maximal oxygen consumption were unchanged during the study duration. Run performance (8 km) improved 3% from T1 to T2 (27:26 to 26:38 min:sec) and 1% from T2 to T3 (26:21 min:sec). A total of 328 individual myofibers were isolated and studied at 15°C. MHC I diameter was 3% lower (P < 0.05) at T2 compared to T1 and 4% smaller at T3 compared to T2. MHC I and Ila fibers were 18 and 11 % stronger (P < 0.05) respectively, from T1 to T2. MHC I fibers produced 9% less force (P < 0.05) after the taper (T2-T3) while MHC Ila fibers were 9% stronger (P < 0.05). Specific tension (Po/CSA) increased (P < 0.05) 38 and 26% for MHC I and Ila fibers, respectively from T1 to T2 and was unchanged with the taper. Maximal shortening velocity (Vo) of the MHC I fibers decreased (P < 0.05) 23% from T1 to T2 and 17% from T2 to T3. MHC I peak power decreased (P < 0.05) 20% from T1 to T2 and 25% from T2 to T3. Power corrected for cell size decreased (P < 0.05) 15% from T2 to T3 and was 24% lower at T3 compared to T1 for the MHC I fibers only. MHC Ila diameter, Vo, peak and normalized power were unaltered during the study duration. These data suggest that myocellular function is sensitive to changes in run training and it appears that MHC I fibers are moreaffected than MHC IIa fibers. Furthermore, the increase in interval training with the taper may have offset the modest reduction in training volume and prevented any positive adaptations at the cellular level. / Human Performance Laboratory