摘要:

ABSTRACT.The assumption was made that finalists in state wrestling tournaments were the best example of well conditioned athletes who were effectively competing at their minimal body weights and that their body dimensions could be used to predict a minimal wrestling weight for other high school students. Anthropometrical measurements (height, diameters, circumferences, skinfolds) were obtained from 582 state finalists and 835 “average” scholastic wrestlers in the state of Iowa. In addition, selected growth and body weight changes during a one year period were secured from 177 and 2,287 students respectively. Comparisons between the two groups indicated that the state finalists were older, had wider diameters, smaller circumferences and lower skinfold values than the average wrestlers. Using height and selected diameter measures, a multiple regression equation was selected that had a correlation coefficient of .93 with the actual body weight of the finalists. It was concluded that the minimal weight prediction equation, when reinforced by physician judgment on marginal cases, could provide a scientific yet practical, inexpensive and effective method to reduce many of the problems created by the “making of weight” by high school wrestlers.

ISSN:0025-7990    

出版商:OVID    

年代:1973

数据来源: OVID

摘要:

ABSTRACT.Data on the age at menarche were collected from 66 college age female track and field athletes and on 30 non‐athlete females of college age. The athletes were classified into five categories: sprinters, distance runners, jumpers (including hurdlers), discus and javelin throwers, and shotputters. The mean age at menarche was significantly earlier in non‐athletes (&OV0398; = 12.23 years) than in the track and field athletes, who did not differ statistically in menarcheal age among themselves. The mean age at menarche for all athletes combined was 13.58 years.

ISSN:0025-7990    

出版商:OVID    

年代:1973

数据来源: OVID

摘要:

ABSTRACT.The changes in minute ventilation (&OV0312;E), tidal volume (VT), and breathing frequency (f) were studied in eleven subjects during and immediately after exercise of various intensity. The intensity of exercise affected the offset responses. Peak expiratory flow and f consistently decreased immediately following exercise. However, VTdid not immediately change following light and moderate work loads and increased following work loads of heavy and severe intensity. The changes in endtidal CO2approximately parallelled those of VT. Since f and VTchange reciprocally immediately following high levels of work, it appears that the mechanisms of control of these parameters differ. This mixed offset response results in a small decrease in VEimmediately following exercise and suggests that the neurogenic stimulus to ventilation which is removed by the cessation of motion, plays a relatively minor role, quantitatively, in the exercise hyperpnea under these conditions and primarily by affecting f.

ISSN:0025-7990    

出版商:OVID    

年代:1973

数据来源: OVID

摘要:

ABSTRACT.The purpose of this study was to determine the relative importance of the factors intensity and distance in interval training on maximal aerobic power (max&OV0312;O2). Three programs were used: (1) high‐intensity, short‐distance sprints (Group S); (2) low‐intensity, long‐distance runs (Group L): and (3) a combination of both (Group M). Following 7½ weeks of training 5 days per week, significant increases in max&OV0312;O2(liters/min) and significant decreases in maximal and submaximal heart rates were found within each group; increases in max&OV0312;O2, (ml/kg‐min) were significant only for Groups S and M. There were no significant differences among groups before or after training. A significant (p < .05) relationship was found between the change in max&OV0312;O2and training intensity indicating that intensity rather than distance is the more important factor in improving max&OV0312;O2. It is proposed that differences in training intensities were due mainly to differences in tissue hypoxia, and that such a relationship is based on proportional differences in the oxidative capacity of skeletal muscle caused by the hypoxic stimulus.

ISSN:0025-7990    

出版商:OVID    

年代:1973

数据来源: OVID

摘要:

ABSTRACT.The purpose of the present study was to determine the relationship between minute‐by‐minute oxygen consumption and work‐output during a progressive step‐increment bicycle ergometer test for maximal oxygen consumption (max&OV0312;O2). Seventy‐five untrained subjects pedalled a Monark ergometer at an initial work‐rate of 900 kpm/min for the first two minutes; the resistance was increased 150 kpm/min each 2 minutes thereafter until the subject stopped pedalling. Within‐individual correlations between work‐output and oxygen consumption clearly showed that oxygen consumption was linearly related to the amount of work performed up to the level of the highest oxygen uptake. When subjects were grouped according to length of riding time (6,8,10,12 min) the correlations increased from r= .75 to r= .94, respectively. In spite of these increasing correlations, the last minute of work was on the average 19% lower than the preceding minute of work. During this time, the oxygen consumption appeared to level of or “peak‐over,” which would at first seem to mean that a true max&OV0312;O2had been attained. However, since the oxygen consumption did not meet established criteria for determining a true max&OV0312;O2(since work decreased), it is recommended that the highest oxygen uptake value recorded during a continuous bicycle ergometer test be termed “peak oxygen” consumption.

ISSN:0025-7990    

出版商:OVID    

年代:1973

数据来源: OVID

摘要:

ABSTRACT.The effects of different weekly exercise exposures on retention of cardiovascular fitness was studied in 21 subjects who were first conditioned by 5 weeks of bicycle ergometer exercise with work rates set to accelerate the heart rate to 80% of its maximum. They were then divided into four groups which exercised one, two, three or four times per week at the same work rate (i.e., heart rate 80% maximum) for five more weeks. Subjects were tested before conditioning (test I), after conditioning (test II), and after exercising at different weekly exposures (test III), for maximum &OV0312;O2, maximum &OV0312;E, maximum HR, 5‐minute recovery HR, O2pulse, &OV0312;EO2, MVV80, FVC, FEV1.0, FEV1.0%FVC, hemoglobin, hematocrit, postexercise blood pressure, and weight. Correlatedttests of differences between tests I and II showed improvement in maximum &OV0312;O2, maximum &OV0312;E, 5‐minute recovery HR, O2pulse, FEV1.0%FVC and a higher hematocrit. Significant F‐ratios (covariance analysis) were found among groups on test III for maximum &OV0312;O2, recovery HR and O2pulse. Employing these three measures in a discriminatory analysis indicated that cardiovascular fitness was retained by exercising three times per week. Pulmonary function improvements were apparently easier to retain than those of cardiovascular function.

ISSN:0025-7990    

出版商:OVID    

年代:1973

数据来源: OVID

摘要:

ABSTRACT.Thirty‐one “post‐coronary” patients have been treated with progressive exercise, and a second series of 14 patients have received hypnotherapy to develop confidence and relaxation.Over the course of a two year program, fourteen of the exercisers have achieved a high level of physical activity. This group shows objective signs of increased cardiorespiratory fitness (a reduction of excess weight and skinfold thickness, an increase of muscular strength, and an increase of predicted aerobic power); an improved relative oxygen supply to the myocardium is also suggested by the lessening of ST segmental depression at a specified exercise heart rate.The remainder of the exercisers failed to share in these benefits. They were older, often had angina or diastolic hypertension, and seemed physiologically unable to attain the necessary intensity of training. These individuals fared no better than those receiving regular hypnotherapy. The latter modality may provide a useful alternative treatment for patients who cannot or will not undertake a vigorous exercise program following myocardial infarction.

ISSN:0025-7990    

出版商:OVID    

年代:1973

数据来源: OVID

摘要:

ABSTRACT.A progressive rise in serum renin activity occurred in female rats with one to four hours of swimming. The exercise‐induced increase in serum renin activity was not attenuated by exercise training. It was, however, blocked by propranolol suggesting that beta‐adrenergic mechanisms are involved in increased renin release induced by exercise stress. The possibility that activation of the renin‐angiotensin system contributes to hemodynamic alterations during exercise should be considered.

ISSN:0025-7990    

出版商:OVID    

年代:1973

数据来源: OVID

摘要:

ABSTRACT.This experiment was divided into two 8‐week phases in order to determine the effects of various combinations of cage restriction, spontaneous running, swim training, and detraining on the force required to separate the medial collateral knee ligament from its bony attachment site in male Wistar rats. Training consisted of swimming in a tank for 15 minutes per day, 5 days per week, with 2 percent body weight attached as an overload. Spontaneous running was provided by permitting some animals to run in exercise wheels attached to their cages. Animals were sacrificed after 8 weeks (N=37) and at the conclusion of the 16‐week experiment (N=56). Statistical analysis of the data indicated that ligamentous separation force was enhanced by physical activity, but detraining did not appear to alter the ligamentous separation force gains which had been acquired through training.

ISSN:0025-7990    

出版商:OVID    

年代:1973

数据来源: OVID

ISSN:0025-7990    

出版商:OVID    

年代:1973

数据来源: OVID