Forty Sprague Dawley rats were randomly separated into one of three experimental groups: Run-Trained (RT), Swim-Trained (SW), or Control (CON). The runners were further separated into 2 groups: Good-runners (RT1), or Poor-runners (RT2) according to their performance on the treadmill. All of the trained groups were endurance trained at approximately 80% V02 max for two hours per day, five days per week in the appropriate mode of exercise. After nine weeks of equi-intensity training, the perimetrial fat pads were removed and the calls isolated. The adipocytes from the trained animals were significantly smaller in volume and diameter than the adipocytes from the controls. Adipocytes from all of the trained groups were significantly more sensitive to insulin than the CON group according to the definition by Kahn (60). The cells from the RT1 and SW groups were significantly more responsive to insulin than both the RT2 and CON groups. The adipocytes from the RT1 group were also significantly more responsive to insulin than the SW group. The differences in cell responsiveness to insulin were highly correlated to the average size of the cells studied. From the data presented in this study threeconclusions were drawn: 1) Both running and swimming at the reported intensity, duration, and frequency have a significant effect on the morphology and metabolism of the isolated adipocyte, 2) Adipocyte morphology, insulin sensitivity, and insulin responsiveness are dependent on the frequency, intensity, and duration of a given exercise training protocol, and 3) Each type of exercise training has its own drawbacks: with swimming, the rats may experience some hypoxia which may alter their metabolic fuel utilization, and during running not all of the animals may be capable or willing to complete the run.Ball State UniversityMuncie, IN 47306

The purpose of this study was to determine the validity of the Ebbeling one-stage submaximal treadmill protocol to estimate maximal oxygen uptake in overweight males and females. Forty-five male and females (36.5±10.9 years; 170.2±9.9 cm; 77.9±9.0 kg) were categorized into overweight groups using a BMI of 25-29.9 kg/m2. The subjects performed a submaximal protocol that consisted of one 4-minute stage with individualized speeds of 2.0-4.5 mph at 5% grade and subsequently performed a maximal exercise test. There were significant relationships between observed and estimated VO2max for males (r=.796), females (r=.426), and gender combined (r=.844). There was an underestimation in the estimation of VO2max in the present study when comparing males (10%), females (26%) and gender combined (17%) subjects. The results indicated that a body mass index between the values of 25-29.9 kg/m2 did create a difference in estimating VO2max in the present study when comparing that to Ebbeling et al. (1991).Ball State UniversityMuncie, IN 47306 / School of Physical Education

No description available.

Adequate recovery from intense exercise is essential to optimise performance and reduce the associated symptoms of tiredness, fatigue and lethargy. The purpose of the study was to :- i. investigate the effects of massage and stretching in delaying the development of fatigue during repeated bouts of dynamic activity and, ii. to investigate the relative effects of massage and stretching on delayed onset muscle soreness (DOMS). Eighteen volunteer males participated in this study. They were randomly allocated into one of six groups of an Orthogonal Latin square design. Subjects performed five repetitions of as many heel raises as possible in 45 seconds. Each repetition was followed by a recovery technique of three minutes duration. This was repeated weekly until each group has had all three recovery techniques. A fatigue index % was calculated from the decline in the number of repetitions from stage 1 to stage 5. Muscle soreness ratings were retrospectively assessed at 12-36 hour after each session. An analysis of variance showed a significant difference in the fatigue indices. Post hoc intergroup comparison using paired T-tests with the Bonferroni adjustment showed a significant difference between rest and massage (p=0.0001) and rest and stretching (p=0.0006). The differences between massage and stretching were not significant. Fourteen (77.8%) and Fifteen (83.3%) subjects showed an improvement in performance following massage and stretching respectively. Massage is associated with significantly less muscle soreness than stretching (p<0,001). DOMS was most frequently found in the stretching group while the lowest incidence and lowest mean ratings of muscle soreness associated with DOMS was found in the massage group. The difference between massage and stretching was marginal (p=046I) and showed a trend that massage is associated with less DOMS than stretching. This suggests that rest is the least beneficial recovery technique, and that massage may be superior to stretching as there is less muscle soreness. / Thesis (M.Med.Sc.)-University of Natal, 1997.

Insulin-like growth factor-I (IGF-I) and its principle binding protein (IGFBP-3) are believed to play a role in mediating the anabolic effects of exercise. The purpose of this study was to assess the effect of 4 months of training on IGF-I and IGFBP-3, and to determine if changes in IGF-I or IGFBP-3 were related to changes in training status. Twelve varsity swimmers (5 males, 7 females) were tested pre-season, and again after 8 and 16 weeks of training. Measures included: VO2 max, nutritional status, athletic performance, subjective symptoms of overtraining, and serum levels of IGF-I and IGFBP-3. There was no significant change across time in VO2 max, athletic performance, IGF-I or IGFBP-3. Resting IGFBP-3 was positively correlated to symptoms of overtraining at week 0 (p=0.017), however, this relationship did not persist at week 8 or 16. These findings can not confirm that resting levels of IGF-I and IGFBP-3 are sensitive markers of training status. / ix, 105 leaves : ill. ; 29 cm.

No description available.

Regular participation in sports is a common practice among the general population. For cardiovascular fitness, the frequency, duration, intensity and mode of the activity must be appropriate for the individual to benefit from the activity. The benefits for cardiovascular fitness are questionable in sports involving high intensity intermittent exercise of short duration. In the past, the procedures for determination of the heart rate and the time-motion characteristics of an activity were cumbersome and time consuming, thus making application to sports an inconvenience. The purpose of this project was to develop a computer based system for matching heart rate data with time-motion characteristics. The system was tested using ice hockey and squash. Subjects were observed during activity. The heart rate data during the activity were collected using a Polar Vantage XL Heart Rate monitor set to record heart rate values in 5-second intervals. The duration and type of activity were entered in the computer in real time using a coding system. Program combined the time-motion analysis with the heart rates that were downloaded from the Polar heart rate monitor. The results were summarized as follows: (1) total time at each intensity level, (2) mean duration at each intensity level, and (3) mean heart rate at each intensity level. Output from the computer program was similar to manual calculations.

This study identified gender-related differences in post-exercise peripheral blood flow and body temperature in neutral environment (21ºC). The subjects were 11 male (22 +/- 4 years) and 14 pre-ovulatory female (23 +/- 3 years) recreational runners VO2max: 62 +/- 5 mL/kg &bull; min for men and 55 +/- 5 mL/kg &bull; min for women). Forearm blood flow rectal (Trec) and forearm skin temperatures (Tsk), and forearm vascular resistance (mean arterial pressure/forearm blood flow) were measured pre-exercise (pre), immediately after (t = 0), and every 15 minutes up to 105 minutes (t = 105) post-exercise (45-minute run at 75% of VO2max). ANOVA revealed main gender effects for Trec, Tsk, and forearm blood flow (men > women) as well as for forearm vascular resistance (women > men). Compared to pre-exercise, Trec at t = 0 showed a similar increase in men (1.3ºC) and women (1.2ºC). Trec decreased thereafter to reach pre-exercise level after 25 minutes in men. In women, Trec kept decreasing to reach a lower than pre-exercise level after 60 minutes (p < 0.05). Tsk was similar at pre and t = 0 for both genders. In contrast, Tsk was lower in women than men (29.0 +/- 1.3 versus 30.7 +/- 1.5ºC) at t = 105 (p < 0.05). Forearm vascular resistance was similar in men and women pre-exercise and decreased by about 50% in both groups at t = 0. Between t = 30 and t = 105, the women increased their forearm vascular resistance up to 35% more than did the men. These observations suggest the existence of gender-related differences in thermoregulatory and cutaneous blood flow responses during recovery from submaximal exercise.

The heart rate achieved with maximal upper limb exercise is quoted as being on average thirteen beats per minute lower than when performing maximal leg exercise. Many canoeists use heart rate monitors during training and seek advice on setting their heart rate training zones. Existing guidelines are based on lower limb-derived heart rates, which may not be appropriate. As canoeists use predominantly their upper limbs during canoeing, it was hypothesized that as their upper limbs are trained, they may achieve heart rates and oxygen consumption similar to those achieved with lower limb exercise. The purpose of this investigation was to compare the relationship between heart rate and oxygen consumption when exercising on either a kayak ergometer or treadmill. Fifteen volunteer canoeists, who compete regularly, were recruited by convenience, purposive sampling and randomly allocated to a V02max test using open circuit spirometry, on either a kayak ergometer or treadmill. They returned within 5 to 7 days for a V02max test on the other apparatus. Their heart rates were also measured during these activities. The heart rate oxygen consumption relationship for upper and lower limb exercise was then analysed. Maximum heart rate was on average only 6 beats per minute lower with upper limb exercise, with some subjects achieving the same or very similar HRmax; the median difference in heart rate maximum was only 4 beats per minute. Although the response of heart rate and oxygen consumption to kayaking and running was similar at any given workload, the heart rate on the kayak was about 8 beats per minute higher at any submaximal workload. V02max. on the kayak was lower than on the treadmill. At any metabolic equivalent, the tidal volume was lower on the kayak and there was a lower respiratory rate on the treadmill. At any tidal volume, the metabolic equivalent was lower on the kayak ergometer. The minute volume on the kayak was higher than on the treadmill, for all but the highest intensities of exercise. Using the leg heart rate max to determine the training zones, a slightly higher (negligible) percentage of arm V0max is achieved at any given percentage heart rate. Kayakers who train regularly, appear to be able to attain similar maximum heart rates with upper and lower limb exercise, but a lower V02max when exercising with their arms. The heart rate oxygen consumption response is the same for upper and lower body exercise; and a reduced HRmax and increased heart rate at any sub maximal workload do not appear to apply to canoeists. It is therefore concluded that heart rate training zones based on leg HRmax are suitable for kayak training. This study has helped distinguish the difference between the heart rates of the upper and lower limbs at any given oxygen consumption in canoeists. The benefits of performing this study have also been to provide better advice to canoeists on how to train using heart rate monitors. / Thesis (M.Med.Sc.)-University of Natal, Durban, 2003.

Post exercise lymphocytopenia is a well documented phenomenon. Studies have reported exercise induced DNA damage in leucocytes and have postulated a possible link to apoptosis. Five subjects of differing fitness levels underwent a ramped treadmill test to exhaustion. Venous sampling was undertaken before, immediately post exercise, and 24 and 48 hours after exercise. Single cell gel electrophoresis showed evidence of single strand DNA breaks (as evidenced by an increase in tail moment measurements using the comet assay) in 100% oflymphocytes immediately after exercise, and in the 24 hour and 48 hour post exercise samples. Flowcytometric analysis oflymphocytes revealed a minimal amount of both apoptosis and necrosis at all time intervals. Lymphocyte apoptosis has again been demonstrated after exercise, however the percentage of apoptosis was a maximum of 4.8% at 24 hours. These findings may in part account for the exercise induced lymphocytopenia and reduced immunity demonstrated by numerous previous other studies. / Thesis (M.Med.Sc.)-University of Natal, Durban, 2001.