摘要:

The aerobic energy cost and certain circulatory and ventilatory responses were studied in 2 human subjects performing work on a bicycle ergometer and employing either concentric (Wcon) or eccentric (Wccc) muscle contractions. Work was performed at intensities ranging from 15–130 Watt and at various speeds (range 20–100 rpm). Oxygen consumption depended upon both work intensity and speed and demonstrated large differences between Wconand Wccc. Heart rate and ventilalation corresponded closely to oxygen consumption but showed definite tendencies to be elevated in Wccc. Calculation of work efficiency as oxygen consumption in excess of values during free-wheeling activity evidenced higher efficiency with increasing pedaling frequency.

ISSN:0025-7990    

出版商:OVID    

年代:1971

数据来源: OVID

摘要:

Measurements of anthropometry, body composition, aerobic capacity, and work efficiency during submaximal work were made on various occupational groups including the Ainu, residing on Hokkaido, the northernmost island of Japan. For the variables studied, no evidence was found for large intergroup differences among the resident populations of Hokkaido that could not be explained by differences in age or physical condition. The relatively small statured residents of Hokkaido appear comparable in aerobic capacity and work efficiency to other small statured people around the world.

ISSN:0025-7990    

出版商:OVID    

年代:1971

数据来源: OVID

摘要:

The interrelationships and orthogonal factors of cardiac time components were studied at rest and 30 seconds after a standard one minute bench stepping exercise in 140 boys, 7 to 14 years of age. Cardiac time components were determined indirectly from simultaneous recording of the carotid pulse wave, phono-cardiogram, and electrocardiogram. The left ventricular intervals were found to be shorter in boys than those reported for middleaged men, with the largest difference being the isovolumetric contraction period, followed by tension period, mechanical and total systole, cycle time, diastole, ejection period and the least difference in the electromechanical lag. The intervals generally increased from age 7 to 14. The intervals shortened as a result of exercise, with lesser shortening in the 7 to 8 age range. Factor analysis of the variables yielded results similar to those reported for middle-aged men in other studies. Factor one represented left ventricular systole, with high loadings for ejection period, mechanical systole, and total systole; factor two represented left ventricular diastole and cycle time with high loadings for these two time components; factor three represented left ventricular tension period; and factor four represented electromechanical lag.

ISSN:0025-7990    

出版商:OVID    

年代:1971

数据来源: OVID

摘要:

The purpose of this investigation was to determine the effects of moderate and heavy exercise on free fatty acid (FFA) mobilization and utilization in human subjects. Thirty-five male subjects performed two exercise tests on a motor driven treadmill. Fifteen minutes of moderate work (40 to 50% maxVO2) was followed by an additional 15 minutes of moderate work in one test, and by 15 minutes of heavy work (80 to 90% maxVO2) in the second test.Plasma glycerol concentration increased during both heavy and moderate exercise. Plasma FFA concentration decreased during the first 15 minutes of moderate exercise; when moderate exercise was continued for 15 more minutes, plasma FFA concentration rose toward the former resting level. When heavy exercise was performed, following 15 minutes of moderate exercise, the initial decline in plasma FFA concentration continued. During heavy exercise the percentage in plasma FFA of C18:2decreased, while that of C18:2increased. The opposite was true during moderate exercise. It is concluded that FFA mobilization and utilization were enhanced during both moderate and heavy exercise. FFA utilization during heavy exercise exceeded that during moderate exercise. Blood lactate concentration increased only when heavy exercise was performed and did not appear to inhibit FFA mobilization.

ISSN:0025-7990    

出版商:OVID    

年代:1971

数据来源: OVID

摘要:

Sustained handgrip strength tests were carried out on five subjects. The interindividual coefficient of variation of the grip times was 16%, the intraindividual coefficient of variation was 10%. There was an exponential relationship between contraction strength and grip times, with mean times of 977 sees for a grip of 20% of maximum grip strength and 51 sees for a 70% grip. At the breaking point, mean heart rate was increased 61 beats/min and mean arterial pressure was increased 82/55 above resting. There was no training effect on endurance time from handgrips held to the breaking point at least every other day for ten weeks. Exposure to 3700 m altitude did not reduce the grip time, or alter the heart rate and blood pressure responses, but did result in an increase in recovery forearm blood flow. Changing inspired air to 9% oxygen surprisingly increased the grip time by 12% and it was concluded that hypoxia was not a major factor limiting the endurance time of a sustained grip.

ISSN:0025-7990    

出版商:OVID    

年代:1971

数据来源: OVID

摘要:

A series of anthropometric dimensions were taken on 66 college age female track and field athletes and on 30 non-athlete college age (range: 17.6–25.0 years) females. The athletes were classified into five categories: sprinters; distance runners; junipers (including hurdlers); discus and javelin throwers; and shot-putters. The sprinters are short-legged and muscular, with especially muscular arms. The jumpers and hurdlers are longer-legged, muscular and linear in build, while the throwers are tallest and heaviest, with broad shoulders and hips, large muscles and more body fat. The distance runners are small, with narrow shoulders and hips, and slight in muscularity. The non-athletes are most like the distance runners in overall size. The controls, however, have more body fat and are slightly broader in build.

ISSN:0025-7990    

出版商:OVID    

年代:1971

数据来源: OVID

摘要:

The Cattell Sixteen Personality Factor Test (16 P. F.) was administered to varsity football players (N=246) who were attending a small private college (n=50); an Ivy League University (n=69); a Big-Ten University (n=83); and a small state supported college (n=44).The purpose of the study was to determine if there were significant differences in team personality profiles.Personality profiles of the four teams were subjected to Multiple Discriminant Function Analyses. The null hypothesis that no significant differences existed in personality profiles between the four teams was rejected.Separate between-teams Multiple Discriminant Function Comparisons revealed that the Big-Ten team's profile was significantly different (.05 level) from each of the other three teams. Significant between teams differences in personality were not found between the small private college, the Ivy League University and the small state-supported college.Univariate F test comparisons showed that the teams were found to be significantly different (.01 level) on factors: I, tough-minded vs. tender-minded; N, forthright vs. shrewd; Q1, conservative vs. experimenting. The Big-Ten team was more tough-minded, shrewd and conservative.At the .05 level of significance the teams were found to differ in personality on factors: M, Practical vs. Imaginative; O, self-assured vs. apprehensive and Q2Group Dependent vs. Self-sufficient. The State College team was found to be more imaginative than the other three teams. The Ivy League team was found to be more self-sufficient and more self-assured than either of the other three squads.

ISSN:0025-7990    

出版商:OVID    

年代:1971

数据来源: OVID

ISSN:0025-7990    

出版商:OVID    

年代:1971

数据来源: OVID