摘要:

ABSTRACT.One hundred and two sedentary and fortysix active adult Japanese females, whose ages ranged from 20‐62 years, were tested for maximal oxygen intake (&OV0312;o2max) on a bicycle ergometer. The active females participated in a regular physical conditioning program. For the sedentary females, the mean &OV0312;o2max's in ml/kg · min were 32.4 for 20‐29 years, 27.9 for 30‐39 years, 26.0 for 40‐49 years and 24.4 for 50‐62 years. For active females, the average &OV0312;o2max values were 37.5 for 20‐29 years, 31.9 for 30‐39 years, 28.8 for 40‐49 years and 27.3 for 50‐59 years. &OV0312;o2max was significantly higher at all ages in the active group (p < 0.05). The rate of decline of &OV0312;o2max as a function of increasing age after the twenties was 0.283 ml/kg · min per year for sedentary females and 0.316 ml/kg · min per year for active females; the respective regression equations being Y = ‐0.283 X + 38.5, and Y = ‐0.316 X + 43.3.

ISSN:0025-7990    

出版商:OVID    

年代:1974

数据来源: OVID

摘要:

ABSTRACT.Continuous and intermittent constant power output (960 kgm/min) bicycle ergometer work was performed at 40, 60 and 80 rpm by 10 highly fit male subjects. Metabolic cost (reflected by heart rate, oxygen uptake, ventilation, lactate debt and oxygen debt) was held relatively constant among pedalling rates, but was significantly elevated for continuous versus intermittent work. In spite of the equivalent metabolic cost, ratings of perceived exertion (RPE) differed significantly among pedalling rates and demonstrated a non‐linear parabolic relationship with pedalling rate. Pedalling at 60 rpm was perceived as the least stressful rate. In addition, continuous work performed at 60 rpm was not perceived to be significantly more stressful than intermittent work performed at 40 and 80 rpm in spite of the elevated metabolic cost of continuous work. These results suggest that factors other than the metabolic cost of a given work task may strongly influence perceptual ratings. Possible influencing factors are discussed.

ISSN:0025-7990    

出版商:OVID    

年代:1974

数据来源: OVID

摘要:

ABSTRACT.The purpose of this study was to describe anthropometric and physiological characteristics of successful, high‐ability wrestlers who tried out for the U.S. Olympic team. The subjects varied more in height and body weight than world class athletes in other sports who have been studied more often. This heterogeneity, in regards to height and weight, allowed an interesting comparison of top athletes, of different size, who all perform the same sports tasks. The 19 wrestlers had a mean &OV0312;o2max of 53 ml O2/kg · min. There was no difference in the means of the aerobic capacities of the 48‐100 kg group who made the Olympic team (N = 9), 54 ml O2/kg · min, and those who did not (N = 8), 55 ml O2/kg · min. The unlimited class wrestlers (N = 2) had a lower mean &OV0312;o2max of 40 ml O2/kg · min; neither made the team. These &OV0312;o2max's of the wrestlers were found to be lower than values reported elsewhere for endurance athletes, but similar to values reported for other wrestlers and football players. The estimated mean body fat of those wrestlers who were trying to lose or maintain their weight was 9.8%. Those who were intentionally increasing their weight had body fats of 13 to 27%. The lighter subjects competed in weight classes much closer to their estimated fat free body weight than did those in the heavier classes.

ISSN:0025-7990    

出版商:OVID    

年代:1974

数据来源: OVID

摘要:

ABSTRACT.Our purpose was to resolve the disagreement as to the number of calories expended per unit distance for walking and running. The caloric costs of walking and running one mile on a treadmill were calculated for eight men and eight women. The subjects walked at a speed of 82 ± 3 m/min (X ± SD) and each ran at a speed that was regarded subjectively as comfortable. The average speed at which the mile was run was 195 ± 25 m/min for men and 137 ± 4 m/min for women. The average R measured during the walk was 0.86 and during the run, 0.96. The gross caloric cost of walking was 1.08 ± 0.06 kcal/kg per mile for men and 1.15 ± 0.08 kcal/kg per mile for women, and the cost of running was 1.57 ± 0.09 kcal/kg per mile for men and 1.73 ± 0.09 kcal/kg per mile for women. The running required significantly more kcal/kg per mile than walking (P < 0.001) and the women used significantly more calories for both running and walking compared to the men (P < 0.01). The net caloric cost of walking was 0.76 ± 0.07 kcal/kg per mile for men and 0.83 ± 0.08 kcal/kg per mile for women, and the cost of running was 1.43 ± 0.08 kcal/kg per mile for men and 1.53 ± 0.09 kcal/kg per mile for women. The difference between the run and walk was highly significant (P < 0.001) and the women used significantly more calories than men for both activities (P < 0.05). Possible reasons for the small but statistically significant difference between men and women are discussed. It was concluded that running a given distance required more calories than walking the same distance.

ISSN:0025-7990    

出版商:OVID    

年代:1974

数据来源: OVID

摘要:

ABSTRACT.The effect of exercise, either long or short term, on levels of 2,3‐DPG and P50are at present controversial. The present study compared the effects of shortterm maximal exercise (average time 5 min 35 sec, maximal group) on levels of 2,3‐DPG and P50to those after a 10 mile road race (average time 51 min 36 sec, endurance group). The resting levels of 2,3‐DPG of both groups of athletes were significantly higher (P < 0.01) than the mean for a group of sedentary males simultaneously determined. The resting P50value‐for endurance group athletes was also significantly elevated. After short‐term maximal exercise (maximal group), a mean 15% increase in 2,3‐DPG with an increase ofin vitroP50(7.4;37C)for 27.2 ± 0.5 to 30.0 ± 0.9 mmHg was observed. On the other hand after prolonged endurance exercise (endurance group), a small but significant (P < 0.05) decrease in 2,3‐DPG and a decrease ofin vitroP50(7.4;37C)from an elevated resting level of 28.9 ± 1.5 mmHg to the normally determined sedentary value (26.7 ± 1.5 mmHg) resulted. Different stimuli are involved in short‐term anaerobic maximal exercise compared to prolonged aerobic exercise and a model is presented to account for the alterations in 2,3‐DPG and oxy‐Hb affinity in the two types of exercise.

ISSN:0025-7990    

出版商:OVID    

年代:1974

数据来源: OVID

摘要:

ABSTRACT.Thirty‐six boys, aged 11‐13, were tested on a bicycle ergometer prior to and following a six week training program. The subjects were ranked according to their &OV0312;o2max, blocked into three fitness levels and then randomly assigned to one of the four treatment groups. The first group (T1) trained at a heart rate of 170‐180 beats/min; the second group (T2) at 150‐160 beats/min; the third group (T3at 130‐140 beats/min; and the fourth group (T4acted as a control. The training was conducted on a bicycle ergometer three times a week, 12 min per session. Following training, the heart rates decreased significantly (P < .05) in the three training groups and blood lactate concentration decreased significantly (P < .05) in the T1group (T3at 130‐140 beats/min; and the fourth group ing groups demonstrated significant (P < .01) increases in physical performance with training, while the &OV0312;o2max, blood lactate concentration and O2pulse increased significantly (P < .05) in the T1group only at maximal work load.

ISSN:0025-7990    

出版商:OVID    

年代:1974

数据来源: OVID

摘要:

ABSTRACT.Motor fitness data on 606 male and 499 female trainable mentally retarded (TMR) children aged 6‐19 in State Schools for Retarded Children in Missouri were compared to published norms for educable mentally retarded (EMR) and normal children for height, weight, flexed arm hang, 300 yard run‐walk, 50 yard dash, situps in 30 seconds, softball throw for distance, and standing broad jump. The TMRs exhibited considerable impairment on all motor variables. The degree of impairment suggested a curvilinear relationship between intelligence and skill proficiency. The interquartile ranges of the various skills were considerably wider for the TMRs than for EMRs or normals. There were age related increases in ability but plateaus or even decrements in performances occurred in older groups. The typical male‐female similarities and differences on motor proficiency appeared to be exhibited by the TMR children. Possible explanations for the reduced motor ability of the TMR children included intellectual complexity of motor acts, generalized genetic and/or environmental impairment, and lack of curricular attention to basic physical fitness needs of TMRs.

ISSN:0025-7990    

出版商:OVID    

年代:1974

数据来源: OVID

摘要:

ABSTRACT.Twelve male subjects performed submaximal and maximal contractions of the elbow flexors concentrically, isometrically, and eccentrically utilizing a Cybex dynamometer. Constant angular velocities between zero and 24 rpm were maintained independent of the force produced by the subject. The average torque produced and the average value of the integrated EMG were determined during the range of elbow movement between 80° and 125° and at 102° for isometric contractions. The average torque produced during maximal eccentric contractions was almost twice that of maximal concentric contractions. However, the degree of motor‐unit involvement was not significantly different between the two types of maximal contractions. The force‐velocity relationship approximated an inverted S‐shape curve with the isometric force falling between the eccentric and concentric values. Concentric force decreased only 17.4% as the velocity increased from 1.5 rpm to 24 rpm.

ISSN:0025-7990    

出版商:OVID    

年代:1974

数据来源: OVID

摘要:

ABSTRACT.By use of electromyographic techniques total reaction time can be fractionated into premotor and motor times roughly corresponding to central processing and motor function output; and, similarly, total reflex time can be fractionated into receptor‐nerve latency and motor times. Fractionated reaction time for right knee extension, fractionated patellar reflex time, and isometric knee extension strength was assessed on six female and five male subjects over four stabilization days. On the fifth day subjects were administered six bench‐stepping bouts. Each bout consisted of 1,383 kg/m of work at a stepping rate of 30/min. After each bout fractionated reaction and reflex times and isometric strength was assessed. A 17.4% strength decrement after the sixth bench‐stepping bout resulted. No significant changes occurred in fractionated reaction time components but total reflex and reflex motor times increased linearily over the bench stepping bouts. Results suggested a central nervous system compensatory process which allowed for unaffected volitional reaction time performance even though significant strength loss and lengthened reflex time were present. The results also suggested that simple reaction time is not a reliable indicator of the onset of significant muscular fatigue.

ISSN:0025-7990    

出版商:OVID    

年代:1974

数据来源: OVID

摘要:

ABSTRACT.The role of body weight, leg volume, and leg weight as determiners of the ability to produce work output during constant load (97 rpm at 34 kpm/rev) cycling of short duration (2 min) was studied. Body weight, leg volume, and leg weight accounted for approximately 41, 36, and 26 percent common variance in total work output, rsepectively. In combination (R= .68) the three variables predicted 46 percent of the variance in performance. Body weight, leg volume, and leg weight were shown to be of little importance during the initial seconds of performance, becoming increasingly more important as consistent decrement in work output occurred. The performance test resulted in substantial and consistent individual differences as revealed by the test‐retest reliability ofr= .92.

ISSN:0025-7990    

出版商:OVID    

年代:1974

数据来源: OVID