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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

This study compared bone mineral index (BMI, gm/cm²) of the femur, spine, and radius, measured by photon absorptiometry in various groups of eumenorrheic female athletes. The sample included body builders (11), swimmers (13), runners (5 collegiate, 11 recreational), and inactive controls (18) averaging 25 years of age, ranging from 17 to 38 years. Lumbar vertebral BMI for body builders (1.40 gm/cm²) was significantly (p ≤ 0.05) greater than controls (1.25 gm/cm²). The body builders' femoral neck BMI (1.09 gm/cm²) was significantly greater than swimmers (0.97 gm/cm², recreational runners and controls (0.95 gm/cm²). Years of exercise history and calcium consumption were not significant predictors of BMI. Correlation coefficients between fat-free body and all BMI sites were significant and more closely related to bone mineral than other variables (weight, height, weight/height²). Correlation coefficients for proximal and distal radius BMI and femoral and spine BMI were significant, the distal radius having higher association.

The purpose of this study was to assess the changes in maximal oxygen consumption and cardiorespiratory responses to maximal treadmill exercise of men, who engaged in intense physical training for more than 35-years. Thirteen men were first studied in 1969 and were re-examined in 1992 as a 25-year follow-up. The men were divided into two groups, group 1 (G1) and group 2 (G2). G1 (current age = 54.6 years) consisted of seven men who were Division I cross country runners in the late 1960's, and G2 (current age = 67.5 years) were highly active at the initial testing and were 14 years older than the men of G1 at all test dates. A maximal exercise test revealed a significant decrease in absolute and realtiveVO2ma, over the 35-years for both G1 and G2. G2 experienced a significant decline in VO2max when expressed in relative and absolute terms after the age of 56.5 years which occurred after the 25-year test. Maximal heat rate decreased over the 35-year period for both G1 (187.7 to 165.8 bpm) and G2 (181 to 164.7bpm), however only GI revealed a trend between the 25-and 35-year tests. O2pulse significantly decreased from the initial testing to the 35-year period in G2 (23.1 to 19.5 ml/beat). Body composition changes were evident with aging in that both GI and G2 had a significant increase in percent body fat over the 35-years however, only Gl had a significant increase in body weight at both the 25-and 35-year follow-up.These data suggest that aging and a reduced training regimen may have a significant effect upon VO2m and cardiorespiratory and body composition measures. It appears that after the age of 56 years, a greater reduction in VO2max occurs, which is accompanied by greater changes in stroke volume. Although the aerobic capacity of these men declined over the 35-year period, the values obtained by all men far exceeded the values reported for sedentary and less active men in other studies. Therefore, as previously reported, aging is associated with a reduction in aerobic capacity, however continued endurance training can reduce the rate at which aerobic capacity declines. / Fisher Institute for Wellness and Gerontology

Fung Man-yi, Wendy. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references (leaves 84-106). / Text in English; abstracts and appendices in English and Chinese. / Fung Man-yi, Wendy. / Acknowledgments --- p.i / Presentation --- p.iii / Abstract --- p.iv / Table of Contents --- p.viii / List of Tables --- p.x / List of Figures --- p.xi / Chapter CHAPTER ONE --- Introduction --- p.1 / Research Background --- p.1 / Purpose of the Study --- p.5 / Justification of the Study --- p.6 / Hypotheses --- p.6 / Definition of Terms --- p.7 / Assumptions --- p.8 / Delimitations --- p.8 / Limitations --- p.9 / Significance of the Study --- p.9 / Chapter CHAPTER TWO --- Review of Literature --- p.10 / "Engergy Metabolism During Prolonged, Submaximal Exercise" --- p.10 / "Causes of Fatigue During Prolonged, Submaximal Exercise" --- p.16 / Factors Influencing Muscle Glycogen Resynthesis During Recovery --- p.21 / Factors Influencing Rehydration During Recovery --- p.27 / Effect of Muscle Glycogen Replenishment During Recovery on Subsequent Endurance Capacity --- p.30 / Effect of Rehydration During Recovery on Subsequent Endurance Capacity --- p.32 / Effect of Glycemic Index Meals Before Exercise on Exercise Performance --- p.33 / Chapter CHAPTER THREE --- Methodology --- p.37 / Participants --- p.37 / Equipment and Instrumentation --- p.37 / Standardized Experimental Procedures --- p.38 / Collection and Analysis of Blood Samples --- p.42 / Preliminary Measurements --- p.45 / Dietary Analyses and Training Control --- p.50 / Preliminary Testing --- p.51 / Statistical Analysis --- p.54 / Chapter CHAPTER FOUR --- Results --- p.56 / Run Time to Exhaustion --- p.56 / Dietary Analysis --- p.57 / Postprandial Responses of the Test Meals During Screening Session --- p.58 / Postprandial Responses During Recovery --- p.60 / Responses During Exercise and Recovery --- p.62 / Body Mass Changes and Fluid Balance --- p.74 / Changes in Plasma Volume and Urine Volume --- p.75 / Summary of the Results --- p.76 / Chapter CHAPTER FIVE --- Discussion --- p.77 / Recommendations and Applications --- p.83 / References --- p.84 / Appendixes --- p.107

Siu Ming Fai Parco. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (leaves 101-117). / Text in English; abstracts in English and Chinese. / Siu Ming Fai Parco. / Acknowledgments --- p.i / Abstract --- p.iii / Table of Contents --- p.vii / List of Tables --- p.ix / List of Figures --- p.x / Chapter CHAPTER ONE --- Introduction --- p.1 / Research Background --- p.1 / Purpose of the Study --- p.6 / Hypotheses --- p.6 / Definition of Terms --- p.7 / Assumptions --- p.8 / Delimitations --- p.9 / Limitations --- p.9 / Chapter CHAPTER TWO --- Review of Literature --- p.10 / Importance of Muscle Glycogen Resynthesis During Recovery from Exercise --- p.10 / Factors Affecting Muscle Glycogen Resynthesis --- p.10 / Muscle Glycogen Resynthesis and Subsequent Endurance Capacity --- p.17 / Importance of Rehydration on Recovery from exercise --- p.22 / Factors Affecting Rehydration --- p.22 / Rehydration and Subsequent Endurance Capacity --- p.25 / Glycemic Index Foods and Exercise --- p.26 / Definition of Glycemic Index (GI) --- p.26 / Ingestion of GI Foods Before Exercise --- p.28 / Ingestion of GI Foods During Recovery --- p.33 / Frequency of CHO Ingestion and Exercise --- p.36 / Chapter CHAPTER THREE --- Methodology --- p.39 / Participants --- p.39 / Equipment and Instrumentation --- p.39 / Preliminary Measurements --- p.40 / Dietary Analysis and Training Control --- p.45 / Preliminary Testing --- p.46 / Standardized Experimental Procedure --- p.51 / Collection and Analysis of Blood Sample --- p.57 / Statistical Analysis --- p.61 / Chapter CHAPTER FOUR --- Results --- p.62 / Run Time to Exhaustion --- p.63 / Dietary Analysis --- p.63 / Postprandial Responses of the Prescribed Foods During Screening Test --- p.64 / Postprandial Responses During Recovery of Main Trial --- p.67 / Metabolic and Physiological Responses During Exercise and Recovery --- p.70 / "Body Mass Change, Fluid Balance and Urine Volume" --- p.89 / Changes in Plasma Volume --- p.90 / Summary of the Results --- p.91 / Chapter CHAPTER FIVE --- Discussion --- p.92 / Recommendations and Applications --- p.99 / References --- p.101 / Appendices --- p.118

Access to abstract permanently restricted to Ball State community only / Access to thesis permanently restricted to Ball State community only / School of Physical Education, Sport, and Exercise Science

The purpose of this study is to determine physiological adaptations in trained male high-school runners before and after high-intensity training associated with a crosscountry season. Testing occurred on five separate occasions at the Human Performance Laboratory. After the first familiarization session, the subjects performed a treadmill graded exercise test in which maximal oxygen consumption and ventilatory threshold was measured. Submaximal oxygen consumption and blood lactate concentration at three running speeds (10, 12, and 14 km'hf 1 at 0% grade) was determined in a second testing session. After the cross-country season (13 weeks) the subjects returned to the laboratory and performed the same graded exercise and submaximal exercise tests. VO2max significantly increased, VT tended to increased, however, not significant. There were no changes in submaximal economy or lactate except for significant decline in blood lactate at 14 km hf' . Although these variables are associated with endurance performance in adults, there is very little information available regarding the effects of endurance training on these variables in the adolescent age group. Knowing the extent of the adaptations will help to optimize the training programs for age group. / School of Physical Education