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to examine the effect of cycle phase or a low dose oral contraceptive on exercise performance in young women.As controls, 15 men were tested twice by a maximal treadmill test (Vo2 max) and by an endurance run 14 d apart to determine performance variability from causes other than hormonal fluctuations. Ten women ages 18-30 were then tested for Vo2 max and endurance in the same way in both the follicular and the luteal phase (random order, ovulation assessed by sonography). They were then randomly assigned to placebo (n = 3) or oral contraceptive (1 mg norethindrone and 35 micrograms ethinyl oestradiol) (n = 7) for 21 days. Tests were repeated during the first and third weeks of treatment. Vo2 max and endurance tests were compared in the men and control cycle of the women by using independent t tests on percent change. The data for both cycles in the women were analysed by repeated measures ANOVA.There was no difference in per cent change in total test time, Vo2 max, or breathing frequency between the men and women in either test. Data obtained during the Vo2 max test revealed no difference between the follicular and luteal phases of the menstrual cycle for total test time [11.8 (SD 2.3) v 12.6 (2.3) min], Vo2 [41.6 (12.1) v 39.7 (11.4) ml.kg-1.min-1], or breathing frequency [26.8 (3.5) v 27.3 (9.9) breaths.min-1] respectively, or during the first and third weeks of treatment [total test time 12.0 (2.5) v 12.8 (2.4) min; Vo2 37.3 (7.4) v 41.0 (12.4) ml.kg-1.min-1; breathing frequency 27.8 (4.2) v 27.7 (3.4) breaths.min-1, respectively]. Data obtained during the endurance test revealed no difference between the follicular and luteal phase of the menstrual cycle for total test time [20.5 (15.7) v 16.2 (8.5) min], Vo2 [37.5 (9.4) v 32.9 (8.1) ml.kg-1.min-1], or breathing frequency [32.0 (6.0) v 33.2 (5.1) breaths.min-1, respectively], or during the first and third weeks of treatment [total test time 32.3 (34.9) v 30.6 (30.1) min; Vo2 33.9 (10.1) v 35.2 (8.6) ml.kg-1.min-1; breathing frequency 34.0 (5.9) v 34.8 (5.3) breaths.min-1, respectively].Neither cycle phase nor a low dose oral contraceptive containing 1 mg norethindrone adversely affects performance during a maximal treadmill test or endurance run.The authors examined the effect of cycle phase or a low dose oral contraceptive on the exercise performance of young women. As controls, 15 men were tested twice by a maximal treadmill test and by an endurance run 14 days apart to determine performance variability from causes other than hormonal fluctuations. 10 women aged 18-30 were then tested by maximal treadmill test and endurance in the same manner in both the follicular and luteal phase. They were then randomly assigned to placebo or oral contraceptive for 21 days. Tests were repeated during the first and third weeks of treatment. Maximal treadmill test and endurance tests were compared in the men and control cycle of women using independent t tests on percent change. Neither cycle phase nor a low dose oral contraceptive containing 1 mg norethindrone was found to adversely affect performance during a maximal treadmill test or endurance run.

Forty-five men (18-35 years) trained three times a week for eight weeks to determine the effects of four constant-resistant weight training programmes on muscular strength, endurance, body composition and cardiovascular functioning. Subjects were randomly assigned to one of four programmes: Endurance (2 sets of 15 repetition maximum [RM]); Explosive (1 set of 15 RM); Strength 1 (3 sets of 6 RM); Strength 2 (1 set of 10 RM twice weekly and 1 set of 3 RM once weekly). All groups showed significant increases in elbow and shoulder flexion strength with elbow extension strength improved in the Explosive, Strength 2 and Endurance groups. Shoulder extension strength improved the Endurance group and in the Strength 2 group. Maximum oxygen uptake (L/min) and (ml X kg-1 min-1) improved significantly in the Endurance and Strength 2 groups. Lean body weight increased significantly in all groups except the Strength 1 group, but there was no change in % fat for any group. Due to a high drop out rate (55%) and injury related problems, the Explosive technique is not recommended. The Endurance and Strength 2 programmes were most effective for improving physiologic functioning, as assessed in this study.

A simple analytical model for the crawl stroke is described. The swimmer is modelled as a torso with arms rotating like paddle wheels; for simplicity the kick is ignored. Starting with theoretical and experimental estimates for drag coefficents and anatomical data from a male collegiate swimming team, the model was adjusted to fit certain tethered and free swimming data. Its behavior was then compared to that of real swimmers in five different experimental situations and good general agreement was observed. The model was found to require much lower drag forces than are measured experimentally, however, perhaps because the kick was not considered. The model provides insight into several aspects of swimming research, including the relationship between tethered swimming forces and actual propulsive forces during free swimming.

Forces developed during fully tethered swimming by 18 male athletes were measured uding a load call in the tether cable. Three competitive strokes were studied: crawl, breast and back. Arm and leg components of the crawl and breast stroke were observed separately. Attempts were made to correlate peak and mean tether forces with competitive velocities. A positive correlation was observed between mean tether force and velocity in the crawl, particularly among distance specialists. A negative correlation was found between crawl velocity and the peak/mean force ratio. The data also suggest that the kick contributes significant force in both the crawl and breaststroke. In neither case, however, does the whole stroke produce as much force as the sum of the arm and leg components would indicate.

The purpose of this study was to establish the validity and reliability of a hydrostatic weighing method using total lung capacity (measuring vital capacity with a respirometer at the time of weighing) the prone position, and a small oblong tank. The validity of the method was established by comparing the TLC prone (tank) method against three hydrostatic weighing methods administered in a pool. The three methods included residual volume seated, TLC seated and TLC prone. Eighty male and female subjects were underwater weighed using each of the four methods. Validity coefficients for per cent body fat between the TLC prone (tank) method and the RV seated (pool), TLC seated (pool) and TLC prone (pool) methods were .98, .99 and .99, respectively. A randomised complete block ANOVA found significant differences between the RV seated (pool) method and each of the three TLC methods with respect to both body density and per cent body fat. The differences were negligible with respect to HW error. Reliability of the TLC prone (tank) method was established by weighing twenty subjects three different times with ten-minute time intervals between testing. Multiple correlations yielded reliability coefficients for body density and per cent body fat values of .99 and .99, respectively. It was concluded that the TLC prone (tank) method is valid, reliable and a favourable method of hydrostatic weighing.

The effects of walking and aerobic dancing on the bones of 73 recently postmenopausal women have been compared by photon absorptiometry of the distal radius with a control group who did not exercise. The period of observation was six months. Results showed that the control group and the walking group lost statistically significant amounts of bone mineral content (1.6%, and 1.7% respectively), but that the dancing group did not (0.8%). The control group did not show a significant increase in the bone width (0.9%), but both the dancing (1.3%) and walking (1.6%) groups did. Changes in the cross-sectional moment of inertia of the radius were estimated for each subject based on bone mineral content and bone width values. Both exercise groups experienced significant increases in this variable, while the control group did not. Plasma oestrogen levels were not influenced by exercise. The results support the hypothesis that mechanical loading due to exercise may be effective in preventing postmenopausal osteoporosis.

Because both aerobic exercise and fish oil ingestion have been shown to decrease plasma lipids, we examined the effects of combining these modalities in hyperlipidemic subjects. Thirty-four subjects were randomly assigned to one of four groups as follows: fish oil and exercise (FE), N = 7, 50 ml of oil daily and 3 d.wk-1 of aerobic exercise; fish oil (F), N = 7, 50 ml of oil daily; corn oil (CN), N = 10, 50 ml of oil daily; and control (C), N = 10. Blood samples were drawn at baseline and at the end of 4, 8, and 12 wk. The FE and F groups showed significantly lower triglycerides with respect to treatment as compared to the CN and C groups. The FE, F, and CN groups exhibited lower total cholesterol values than the control group but were not different from each other. HDL cholesterol was significantly increased after treatment in the FE and F groups as compared to the CN and C groups. Serum apo-B, LDL cholesterol, and LDL protein decreased significantly in the FE group but not the F group from baseline to 12 wk. VO2max increased and percent fat decreased only in the FE group. In conclusion, aerobic exercise improved the effects of fish oil on LDL cholesterol and apo-B and improved fitness and body composition in hyperlipidemic subjects.