摘要:

Differentiated ratings of perceived exertion (RPE) were obtained from eight low-altitude residents during cycle exercise at sea level (SL) and after acute (< 2 h) and chronic (18 d) exposure to high altitude (4,300 m; HA). Mean Vo2max, was 27% lower with acute HA exposure than at SL and was not significantly changed with chronic exposure. Subjects cycled for 30 min at an exercise intensity requiring 85% of Vo2max. Respiratory exchange measurements and differentiated RPE were obtained at minutes 5,15, and 25 of exercise, and pre-and post-exercise blood samples were collected. Differentiated RPE included a local muscular rating, a central or cardiopulmonary rating, and an overall rating. Despite reduced absolute exercise intensity during acute HA exercise, local RPE were unchanged from SL values. Chronic HA exercise, however, was associated with a significant reduction in local RPE. Blood lactate accumulation during SL exercise was not significantly different from acute HA exercise but was significantly less during chronic HA exercise. At SL, local ratings were significantly greater than central ratings, while neither differed significantly from the overall ratings. None of the differentiated ratings differed significantly during acute and chronic HA exercise; central RPE were highest of the ratings during chronic HA exercise. The ventilatory equivalent for oxygen during HA exercise (both acute and chronic) was significantly higher than at SL. This apparent rearrangement in the relative order of magnitude of these three differentiated ratings suggests an alteration in the relationship between perceptual cues sensed as effort.

ISSN:0195-9131    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

The purpose of this study was to compare the physiologic effects of a program of combined running and weight training (RUN-CWT) with a program of circuit weight training (CWT). Thirty-six females (± age=35.7 yr) and 41 males (± age=36.1 yr) were randomly assigned to RUN-CWT, CWT, and control groups. The training groups participated in 12-wk programs, 3 d-wk−1. Three circuits of 10 weight-training exercises were completed with 12–15 repetitions performed in 30 s at 40% of one-repetition maximum at each station. The 30-min RUN-CWT program included 30 s of running on an indoor track following each CWT station, whereas the 22.5-min CWT program included a 15-s rest period between stations. The RUN-CWT groups had a significant (+17%) increase in Vo2max(females 30.5–35.7 ml-kg−1-min−1and males 39.7–46.3 ml-kg−1-min−1) and strength (females +24% and males +21%), and a significant decrease in body fat percentage (females —3.2% and males — 4.1%). The CWT groups also increased significantly in VO2max( + 12%) and strength (+17%) and decreased in body fat (-3.0%). The controls did not change significantly in any variable. Statistically, one training program was not shown to be superior to the other; thus, both programs of RUN-CWT and CWT were effective in improving measures of physical fitness.

ISSN:0195-9131    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

An approach is presented for developing optimal strategies for distance road racing and cross-country racing, i.e., running, skiing, and bicycling over courses of varying terrain. The course can be divided into segments defined by known properties, and the racer may be characterized by his abilities relative to the course segments and total energy available for completing the course. Functional optimization methods are used to select the racer's velocity in each segment to minimize the total time required to complete the course without exceeding any of the racer's limits. Two characterizations of the racer's total capability concerning course parameters are developed. Using a “distance-life” model based on data, examples of optimal strategies over courses of varying terrain are presented. It is shown that the defined optimal strategy is measurably better than other strategies. Several new concepts are introduced that are easily adapted to such problems and can be used in developing fundamental energy expenditure relations.

ISSN:0195-9131    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

Body composition and physical dimensions were compared between 23 young, experienced wrestlers (mean age ± SE = 11.0 ± 0.21 yr) and 23 school children (11.2 ± 0.24 yr). The wrestlers were among the best wrestlers from local wrestling clubs and averaged 2.7 (± 0.27) yr of experience. They had won 72% (± 1.8%) of the total 75 (± 9.1) matches. The comparison group consisted of volunteers from local elementary schools. Standard densitometric and anthropometric techniques were used to measure the body composition and physical dimensions of each group. The wrestlers were 4 kg lighter (P<0.05) and had a smaller percent fat than the comparison group (13.3 ± 0.66% and 20.0 ± 1.13%, respectively). The weight difference between groups was due to the larger fat weight of the comparison group since lean weight differed by only 0.8 kg. Fat differences were also reflected in the larger skinfolds and “fat” circumferences of the comparison group. No group differences were noted in diameters. It is concluded that compared to other children young experienced wrestlers have similar skeletal structures and lean body weights. The comparison group possessed more body fat.

ISSN:0195-9131    

出版商:OVID    

年代:1982

数据来源: OVID

摘要:

To study the effects of training and aging on aerobic capacity, 8-wk-old female Wistar rats were assigned to training and sedentary, free-eating control groups (N = 10, each). Training involved 5 wk of daily progressive treadmill running reaching an intensity of 26.8 m.min−1on 15% grade for 1 h. Training was maintained at this intensity for an additional 11 wk. The O2maxof trained and sedentary control rats was assessed every 2 wk. Peak O2max(25.4±3.2 ml-min-1; X → SEM) was observed in the trained group at 20 wk of age and represented a 15% increase over the untrained group. When expressed on a relative basis, the peak Vo2maxin trained rats at 20 wk of age was 86.6±8.6 ml · kg−1.min−1or an 8% improvement compared to controls. In control animals &OV0312;O2maxwas also greatest at 20 wk of age (22.0 ± 1.9 ml-min−1; 79.9±6.4 ml-kg−1-min−1). After 20 wk of age, &OV0312;O2maxdeclined in sedentary controls, but was maintained in trained animals through 24 wk of age. Mature trained female animals were approximately 6% heavier than sedentary free-eating controls. Endurance training may stimulate anabolic processes as well as improve and maintain aerobic capacity in the female rat.

ISSN:0195-9131    

出版商:OVID    

年代:1982

数据来源: OVID

ISSN:0195-9131    

出版商:OVID    

年代:1982

数据来源: OVID