ISSN:0025-7990    

出版商:OVID    

年代:1975

数据来源: OVID

ISSN:0025-7990    

出版商:OVID    

年代:1975

数据来源: OVID

ISSN:0025-7990    

出版商:OVID    

年代:1975

数据来源: OVID

ISSN:0025-7990    

出版商:OVID    

年代:1975

数据来源: OVID

ISSN:0025-7990    

出版商:OVID    

年代:1975

数据来源: OVID

ISSN:0025-7990    

出版商:OVID    

年代:1975

数据来源: OVID

摘要:

Eight experienced oarsmen and five inexperienced subjects performed a multi-stage exercise test on a rowing and bicycle ergometer. Oxygen uptake, heart rate and minute ventilation were observed on both exercise modes from light to maximal exercise. Although the o2max values were slightly higher on the bicycle ergometer ( 6.0% and 4.0% for the oarsmen and inexperienced subjects) differences were not significant (P>0.01), nor consistent in all subjects. Max heart rates and lactate levels were similar on both exercise modes. The VE/Vo2ratio, however, was consistently higher on the bicycle than on the. rowing ergometer at maximal exercise for all subjects (7.2% and82%for the oarsmen and inexperienced subjects, (P< 0.01). Apparently, the development of Vo2max on the bicycle ergometer was characterized‘ by a larger VE/Vo2when compared with the rowing ergometer. The cramped position of the body while rowing appears to constrict the abdominal muscles, which may limit their ability to aid in the expiratory phase of the breathing cycle. The forcing up of the abdominal viscera in this position may also constrict the action of the diaphragm during inspiration.

ISSN:0025-7990    

出版商:OVID    

年代:1975

数据来源: OVID

摘要:

ABSTRACTDaily fluctuations in serum enzyme activities during distance running in 3 well-conditioned males were measured for 8 consecutive days. During the study the exercise regimen comprised 8 mile runs on days 1, 2 and 5; a 10.5 mile run on day 3; a 15 mile run on day 4 and resting on days 6–8. Heart rate, rectal temperature, hematocrit, plasma hemoglobin, creatine phosphokinase (CPK, glutamic-oxaloacetic and glutamic-pyruvic transaminases, lactate dehydrogenase (LDH), adenylate kinase (AK), and lactate and pyruvate were measured before and after exercise and during the resting days. Significant increases occurred in heart rate and rectal temperature with each run but were unrelated to enzyme levels. Pre-exercise CPK levels, 49±1 mIU/ml on day 1, rose progressively to 123± 25 mIU/ml on clay 5, and returned to initial control levels by day 8. Post-exercise CPK levels were significantly greater than pre-exercise levels on each running day hut were unrelated to the severity of the exercise. LDH and AK levels did not significantly change with the exercise stress, but pre-exercise AK levels in these trained males were higher than values in non-trained males (10–20 vs. 0–5 mIU/ml) (3). Post-exercise enzyme levels appeared unrelated to final heart rate, rectal temperature or plasma hemoglobin. These results suggest that (1) CPK, unlike the other enzymes studied, is a sensitive index of exercise stress in well-conditioned runners and (2) elevated CPK and AK levels in such runners represent physiologic responses. Appropriate caution should be used in making clinical judgements from these enzyme assays in trained individuals.

ISSN:0025-7990    

出版商:OVID    

年代:1975

数据来源: OVID

摘要:

ABSTRACTThis study was undertaken to determine the effects of O2-enriched gases on performance. Nine trained subjects ran to exhaustion on the treadmill on five different occasions breathing one of a range of hyperoxic gas mixtures—20%, 40%, 60%, 80%, or 100% O2. Each subject worked at a workload determined to be 110% of that necessary to elicit his maximum Os uptake. The exercise bouts were scheduled one week apart to minimize the effects of training and fatigue. The subjects were given no cues as' to the mixtures being breathed or to their running times. The parameters measured included running time, minute ventilation, and heart rate. The results indicate that the maximum performance time increases significantly as the O2fraction of the gas is increased. Contrary to other published literature, 100% O2increases performance significantly over 60% O2. Ventilation at any point in time is decreased when breathing hyperoxic mixtures. This decrease appears to be more a function of breathing frequency than of tidal volume. Terminal heart rates are not significantly different regardless of the O2fraction of the inspired gas.

ISSN:0025-7990    

出版商:OVID    

年代:1975

数据来源: OVID

摘要:

ABSTRACTSwim records data from the U.S. Masters swim program afforded a chance to estimate the decline in swim performance over middle life. Men's records data indicated a falloff in swim performance of slightly less than one percent per year over the ages of 27.5 to 57.5 years. Men's decline in freestyle performance was seen to be essentially the same, regardless of varying oxygen requirements secondary to the distance swum. Men's decline in swim performance for the breaststroke and backstroke events was nearly that of the freestyle. Falloff in men's performance in the butterfly stroke rose to 1.47 percent per year. Women's times showed a decline between 20 to 50 percent greater than that seen for the men. Previous findings of athletes' decrease in pulmonary function over middle age closely parallel the observed decrease in Masters swimmers' records—approximately one percent per year.

ISSN:0025-7990    

出版商:OVID    

年代:1975

数据来源: OVID