摘要:

ABSTRACT.Twelve girls eight to thirteen years of age were studied before and after six and twelve weeks of cross‐country running. Eight untrained controls were tested twice at six week intervals and weighed after 12 weeks. Oxygen consumption, ventilation, and heart rate were measured during continuous increment treadmill runs to maximum. Mean maxVo2increased by 18 percent at 6 weeks and 26 percent at 12 weeks above pre‐training values. Max &OV0312;Ewas unchanged. Heart rates at submaximal and maximal work loads showed moderate but consistent declines in both runners and controls. Three runners lost 0.7 to 2.0 kg during the season, but the rest gained an average of 0.6 kg. Hence, these pre‐adolescent girls were capable of adapting to endurance training in a fashion similar to adults. No detrimental effects were observed save unexplained weight loss in two runners.

ISSN:0025-7990    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

ABSTRACT.The study was conducted to investigate the specificity of training effects accruing from participation in programs of treadmill running and bicycle ergometer riding. Two groups of adult male subjects were pretested using PWC150tests on both the treadmill and bicycle ergometer and were found to be similar (P > .50) in their functional capacity as measured by both tests. For a period of six weeks one group engaged in treadmill running of increasing intensity while the other group participated in a progressive training program on a bicycle ergometer. The groups were subsequently post‐tested on both. The treadmill and bicycle ergometer tests indicated that the treadmill training group had improved significantly in physical working capacity as measured by both tests whereas the bicycle training group had improved significantly only as measured by the bicycle ergometer test. A 2‐way ANOVA for repeated measures was employed to test for suspected interaction between training tasks and PWC150tests. The results identified the existence of significant interaction between the bicycle training program and the bicycle PWC150test. It was concluded that training effects of cycling are more specific than those of running and, therefore the choice of a work capacity test for assessing changes in circulorespiratory functional capacity resulting from exercise is critical.

ISSN:0025-7990    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

ABSTRACT.Different investigations have reported that thead libitumenergy intake of sedentary individuals increases, decreases or remains unchanged following an inincrease in their degree of physical activity. The purpose of this investigation was to measure accurately the post exercise changes in the 24 hour energy intake of 14 sedentary university men aged 21 to 30 years. A practical modification of the food weighing technique was used. The 24 hour energy intake was measured on four consecutive days and the subjects then exercised on two separate occasions, 48 hours apart, running distances of 440 yds and one mile on a motor‐driven treadmill. The measurement of 24 hour post exercise energy intake commenced immediately after the exercise had been completed. The mean control intake was 2673 ± 171 kcal while the post exercise means were 2638 ± 144 kcal and 2699 ± 138 kcal for the 440 yds and one mile runs, respectively. The performance of these running tasks had no measurable effect on the 24 hour energy intake.

ISSN:0025-7990    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

ABSTRACT.The reproducibility of heart rate at rest and in response to standardized ergometric tests on treadmill and bicycle was evaluated by test‐retest. A series of submaximal tests were done on medically eligible middle‐aged men at weekly intervals. The correlation (r) for successive sets of resting heart rates was in the range 0.72‐0.78; mean differences were generally negligible. The r between successive exercise tests was higher (0.69‐0.97). The mean of the second of a pair of tests was uniformly less by 1.0 to 3.4 beats / min than the mean of the first, and in about one‐third of these comparisons the mean difference was statistically significant. Standard Error of the Measurement and Technical Error between successive tests — measures of intra‐individual variability — ranged from 2.0 to 6.7 beats / min, being less for treadmill than for bicycle or resting heart rate. Test reproducibility was similar at different loads of exercise. These data confirm that heart rates at rest and submaximal exercise are sufficiently stable characteristics of healthy middle‐aged men to enable their use for longitudinal assessment of groups and individuals.

ISSN:0025-7990    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

ABSTRACT.There was no correlation between four criteria for maximal &OV0312;2in sixty‐five men, aged 40‐65 years. 78% of subjects had lactic acid values above 8 mMol/l, 74% had heart rates within 5 beats of average maximal for age, 54% had respiratory quotient values over 1.12 and 43% of subjects had &OV0312;2valves below 90% of the expected &OV0312;2for the work load used. There was no difficulty in having these unfit subjects cycle for fifteen minutes. The average max &OV0312;2was about 30 ml/kg min‐1; and as there was no attempt to show a plateau for &OV0312;2, it is preferable to use the term “near maximal” rather than maximal.

ISSN:0025-7990    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

ABSTRACT.Heart‐rate / work level curves were analyzed for 11 racing cyclists. Two trials of an upright bicycle ergometer task continuously increasing to incapacity were performed three days apart. By polynomial curve fitting four meaningful components were found; an initial anticipatory response, a linear heart‐rate / work level phase, a negative quadratic function at high levels of work, and (in two subjects) a trend to a step‐wise increase in heartrate despite the continuously increasing work load. The quadratic component correlated with the maximum work ability at exhaustion: the maximum heart‐rate and the linear rate of change did not.

ISSN:0025-7990    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

ABSTRACT.Maximum oxygen intake of 690 athletic and nonathletic Japanese adolescents were measured by a progressive treadmill exercise test. In the case of non‐athletes, the mean values of max &OV0312;2for boys increased with age and those for girls were almost constant from 12 to 18 years of age. There was a significant correlation (0.883 for boys and 0.597 for girls) between max &OV0312;2and body weight. The regression equations were calculated between them. Comparing nonathletes to athletes, there was a distinct difference in max &OV0312;2in 1/min and ml/kg.min.

ISSN:0025-7990    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

ABSTRACT.Ten healthy men between the ages of 22 and 29 years walked on a motor‐driven treadmill. Loads of 1.4, 1.8, 2, 3, 4, 5, 6, 7, 8, and 9 Mets were sustained for three minutes each, interspersed with three‐minute recovery periods. The heart rates were monitored throughout using a cardiotachometer and ECG preamplifier (Hewlett‐Packard). The initial heart rate (ho) just prior to exercise, the peak heart rate (ĥ), the time to reach a steady‐state heart rate (TU), and the time to recovery following exercise (TD) were measured from each cardiotachometer tracing. On a subsequent day, five of the ten subjects chewed 5.0 mg of the vasodilator, isosorbide dinitrate and then repeated the treadmill study. In the absence of vasodilator, TU and TD gradually increased with loads, TU from 10.7 to 48.6 seconds and TD from 12.7 seconds to 48.8 seconds at 2 and 9 METS, respectively. Following ingestion of the vasodilator, ho and ĥ were consistently slower and TU was consistently prolonged, while TD was essentially unaffected. The results indicate that the rate of heart rate response to physical exercise is related to load, and that the normal response is modified by the pharmacologically vasoactive substance, isosorbide dinitrate.

ISSN:0025-7990    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

ABSTRACT.Two lean and two obese women performed contralateral arm‐leg exercise in environments maintained at two different “effective temperatures” of 21° and 29°C. Variations among relatively steady state skin temperatures, subcutaneous temperatures, and three measures of core temperature were studied under two exercise loads, i.e., 25% and 50% max &OV0312;2. Core and subcutaneous temperatures were found to increase directly with the work load performed. Skin temperatures were related to ambient temperatures, but decreased with higher work load performance. This decrease was attributed primarily to increased evaporative heat loss rather than to changes in blood flow distribution because the skin temperatures and the subcutaneous temperatures of active limbs exceeded those of contralateral inactive limbs. The subcutaneousskin surface temperature gradient was greater at the lower environmental temperature, but increased directly with the work load in the warmer environment as a result of the increased subcutaneous and decreased skin temperatures.

ISSN:0025-7990    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

ABSTRACT.Thirty‐one subjects were trained with weights for seven weeks. At the end of the fourth week, 24 subjects were randomly placed in the treatment‐placebo group which took two capsules daily from 24 numbered bottles for 21 days. Twelve of the bottles contained 5 milligrams of methandrostenolone (Dianabol) per capsule. Oxygen uptake, sperm count, maximum weight lifting and thickness of skinfolds were determined. Also used were cable tensiometry and anthropometric measurements. There was no significant change in oxygen uptake or spermatogenesis. The strength of the treated subjects increased significantly, their mean weight gain was 2.37 kilograms with no significant change in skinfold thickness. Five of eight anthropometric measurements increased significantly.

ISSN:0025-7990    

出版商:OVID    

年代:1972

数据来源: OVID