No abstract

The purpose of this study was to describe body composition, muscular strength, pulmonary function, and aerobic capacity of young swimmers, after 6 years of training. Twelve male members of a competitive swim team, ranging in age for 13 to 16 years, served as subjects. Each subject was measured on 2 separate days at approximately the same time of day on each occasion. On day one, body composition, muscular strength, TLC, FVC, FEV1.0, FRC, RV, and resting DLc0 were determined. On day 2, height, weight, VE max Hr max, and VO2 max were measured. Results indicated that children who train to swim competitively: (1) are lower than average in percent body fat (10.8%) as determined by hydrostatic weighing, (2) are muscularly fit as indicated by the Oregon Cable-Tension Strength Test, and (3) have cardiorespiratory capacities which are greater than one would expect to see in untrained youth of similar ages.

No abstract

An exaggerated exercise blood pressure response (EEBPR) may be associated with an increased risk of hypertension. We hypothesized that aerobic exercise training can decrease EEBPR and the risk for hypertension by decreasing arterial resistance. We studied the effects of aerobic training on the submaximal exercise blood pressure (BP) of eight normotensive young adult AfricanAmerican men with an EEBPR. Subjects were trained on a stationary bicycle at an intensity of 70% peak oxygen uptake (VO 2peak ) for 30 min, three times per week, for 8 weeks. BP, heart rate, cardiac output (CO), stroke volume (SV) and total peripheral vascular resistance (TPR) were measured at rest and during submaximal exercise at a work intensity of 50% VO 2peak . Significance of the training effects were evaluated by comparing the pre-and post-training measures (t-test, p < 0.05). A 15% post-training increase in VO 2peak (34.6 ± 1.4 to 40 ± 1.4 ml/kg/ min) and a 9.5 ml post-training increase in mean resting stroke volume were found. A 16.2 mmHg decrement in mean systolic BP, an 11.5 mmHg decrement in mean diastolic BP, a 120 dyne/s/cm 5 decrement in TPR and a 1.2 l/min increase in CO were detected during the post-training submaximal exercise tests. These results suggest that reductions in TPR may attenuate the EEBPR of normotensive African-American males following an 8-week training regimen of stationary bicycling at 70% VO 2peak . Aerobic exercise training may, therefore, reduce the risk of hypertension in normotensive African-American males by the mechanism of a reduction in TPR. Because of the limited number of subjects, the results of this study should be interpreted cautiously pending confirmation by a larger controlled trial.