摘要:

To measure percent body fat (%F) using hydrodensitometry,“true”underwater weight (UWW) has conventionally been determined from the mean of 8, 9, or 10 UWW trials. Because the procedure is time‐consuming, many subjects are uncomfortable in water, and the elderly often fatigue rapidly, it would be desirable to reduce the number of trials. In 400 Caucasian men (age 35.5 years, height 176.9 cm, mass 85.7 kg) we compared %F estimates derived by four selection methods based on the mean of: (1) three trials with the highest adjacent trial correlations (trials 4, 5, 6) (%P = 22.9%); (2) three successive trials within 100 g (3 ROW) of UWW (22.9%), (3) any three trials within 100 g (3 WIN) of UWW (22.8%), and (4) trials 8, 9, and 10 (22.8%). Repeated measures analysis of variance (ANOVA) revealed no significant (p>0.05) difference between groups in %F using the four respective methods for selecting true UWW. A repeated measures ANOVA, using %F as the dependent variable, comparing selection methods across age quartiles revealed no significant (p>0.05) differences among the methods and no significant“age by trials”interaction. These data suggest that, regardless of age, in contrast to the convention of performing 10 or more trials to estimate %F, methods 3 ROW, 3 WIN, and T4‐6 are sufficient to achieve true UWW, resulting in a valid estimation of %F.

ISSN:1057-8315    

DOI:10.1080/15438629509512022

出版商:Taylor&Francis Group    

年代:1995

数据来源: Taylor

摘要:

The goal of this study was to compare various methods of anaerobic threshold (AT) determination and to estimate its importance for both the prescription of appropriate physical activity and long‐term follow‐up evaluation in patients with chronic heart failure (CHF). Twenty‐eight persons (New York Heart Association Classification II, III) passed a symptom‐limited spiroergometrical test; some of them were serially measured. The incremental work rate was graded by 0.25 W‐kg‐1every 4 minutes. AT was determined from ventilatory parameters (VT), on the one hand, and from base excess changes (—BET), on the other. VT was determined in 79% and—BET in 50% of patients. The correlation between other functional parameters and both VT and‐BET parameters was close (r = 0.94 for heart rate, for example). The possibility of making an AT determination decreased in Weber's class C patients. AT determination was also possible in persons showing a change in acid‐base balance at rest. Basic functional parameters (heart rate, oxygen uptake) and rating of perceived exertion determined at AT showed a high interindividual variability. The mean value corresponded to 60% of maximum level of exercise tolerance. It was concluded that AT could be determined in a high percentage of persons with CHF even if determination of a clear result decreased with increasing severity of illness. VT could be determined more frequently than‐BET; nevertheless, the results obtained by these two methods were comparable. The AT level was determined to be an objective criterion for definition of illness severity and its progress. AT may be used not only for long‐term evaluation of therapy effectiveness, but also for the prescription of a safe limit for physical activity.

ISSN:1057-8315    

DOI:10.1080/15438629509512023

出版商:Taylor&Francis Group    

年代:1995

数据来源: Taylor

摘要:

A rib injury in an athlete may not always require several weeks of enforced rest, as may be seen in the present case report of an elite‐level distance runner who fell onto his chest while cycling. Essential primary treatment is to determine accurately the presence or absence of any underlying injury such as pneumothorax. If such injury is absent, aggressive initial rehabilitative therapy and appropriate medication, followed by a steady transition back to normal training as comfort permits, can safely minimize loss of physical fitness and competitive down time. Because the athlete described here had been part of a long‐term cardiopulmonary fitness monitoring program, additional physiological and physical data, collected during an 8‐year period, provided a unique opportunity to understand better the effect of temporary debilitation from both a clinical and athletic perspective.

ISSN:1057-8315    

DOI:10.1080/15438629509512024

出版商:Taylor&Francis Group    

年代:1995

数据来源: Taylor

摘要:

The effect of adding external weightstothe body of participants in a 10‐week low‐impact aerobic dance program (3 days/week, 50 minutes/session, 60 to 90% of maximum heart rate [HRmax]) on aerobic power and body composition was studied in 20 college women. Subjects were randomly assigned to either a regular low‐impact aerobic dance group (NWT) or to a low‐impact aerobic dance group (WT) whose participants also carried added weights (1.5 lb/ankle; 3.0 lb/hand) during training. Pre‐and post‐training aerobic power and body composition measurements were made on 17 subjects who completed the program. A repeated measures ANOVA revealed a significant overall reduction in body fat percentage (‐2.9%) and fat weight, and an increase in maximum oxygen consumption (VO2max; 3.2 mL‐kg‐1min‐1; 0.2 L‐min‐1), maximum minute ventilation VEmax; 10.1 L‐min‐1) and fat‐free weight following training (p≤0.05). However, there was no group mean difference between any of the same variables in the WT and NWT groups. In addition, no change before to after training was observed for body weight (‐0.3 kg), HRmax(‐2.2 beats/min), maximum respiratory exchange ratio, and maximum rating of perceived exertion (p>0.05). The present findings indicate that low‐impact aerobic dance is an effective modality for increasing aerobic power and changing body composition in college women; however, routine use of external weights carried by a subject during aerobic dance training fails to impart any additional training benefit in addition to that already derived from the activity.

ISSN:1057-8315    

DOI:10.1080/15438629509512025

出版商:Taylor&Francis Group    

年代:1995

数据来源: Taylor

摘要:

Future spaceflight will require travelers to spend ever‐increasing periods of time in microgravity. Optimal functioning of the immune system is of paramount importance for the health and performance of these travelers. A meta‐analysis statistical procedure was used to analyze immune system data from crew members in United States and Soviet space missions from 8.5 to 140 days’duration between 1968 and 1985. Ten immunological parameters (immunoglobulins A, G, M, D, white blood cell [WBC] count, number of lymphocytes, percent total lymphocytes, percent B lymphocytes, percent T lymphocytes, and lymphocyte reactivity to mitogen) were investigated using multifactorial, repeated measure analysis of variance. With the preflight level set at 100, WBC count increased to 154±14% (mean±SE; p≤0.05) immediately after flight; there was a decrease in lymphocyte count (83±4%; p≤0.05) and percent of total lymphocytes (69±1%; p≤0.05) immediately after flight, with reduction in RNA synthesis to phytohemagglutinin (PHA) to 51±21% (p≤0.05) and DNA synthesis to PHA to 61±8% (p≤0.05) at the first postflight measurement. Thus, some cellular immunological functions are decreased significantly following spaceflight. More data are needed on astronauts’age, aerobic power output, and parameters of their exercise training program to determine if these immune system responses are due solely to microgravity exposure or perhaps to some other aspect of spaceflight.

ISSN:1057-8315    

DOI:10.1080/15438629509512026

出版商:Taylor&Francis Group    

年代:1995

数据来源: Taylor

摘要:

Seven female members of a university cross‐country and track team (mean age, height, and weight were 19.4 years, 160 cm, and 52.7 kg, respectively) were physiologically monitored through 1 year of training and competition. Laboratory assessment included measurement of maximal oxygen uptake (VO2max), ventilation threshold (VT), running economy, percent body fat, elapsed time to exhaustion at VO2maxon a treadmill run, and peak grade (PG) reached on a treadmill test. Physical performance was based on elapsed time for completing the same 5 km cross‐country course at the identical time each year. A statistically significant change was noted in only two variables: elapsed time of treadmill running at VO2max(p=0.03) and 5 km run time (p = 0.04). Two variables were significantly related to 5 km run performance: PG (r =‐0.925) and speed at VT (r =‐0.829). The relationship of VO2maxand run time was not significant (r =‐0.287, p>0.05). The change in only one variable, percent body fat, was significantly related to change in run time (r =‐0.82). It was concluded that a change in VO2max, VT, and running economy is not required in order for running performance to improve. Performance in running 5 km was strongly related to speed at VT and PG achieved at VO2max, whereas improvement in performance was best explained by decreased body fat.

ISSN:1057-8315    

DOI:10.1080/15438629509512027

出版商:Taylor&Francis Group    

年代:1995

数据来源: Taylor

摘要:

This study determined the effect of a 10‐week step aerobics training program on aerobic power and body composition of college‐age women (mean age, 19.4 years). Subjects in the experimental group (n = 21) exercised three times per week for 10 weeks, at an intensity that represented 76% of maximal heart rate. A control group (n = 28) did not exercise. All subjects performed a maximal treadmill test, were hydrostatically weighed, and were measured for maximal buttocks, thigh, and calf girth prior to and on completion of the study. Compared with the control group, the experimental group showed significant (p≤0.05) improvement in peak oxygen consumption (11.7%), maximal minute ventilation (6.7%), and time to exhaustion on the treadmill (33.1%). There was no significant (p>0.05) change in percent body fat in either group. Thus, it appears that step aerobic training can be an effective method of improving aerobic power in college‐age women. However, while the acute caloric requirement of step aerobics compares favorably with other modes of exercise, the duration and frequency of training used in the current study was not adequate to affect body composition positively in this group of women.

ISSN:1057-8315    

DOI:10.1080/15438629509512028

出版商:Taylor&Francis Group    

年代:1995

数据来源: Taylor

ISSN:1057-8315    

DOI:10.1080/15438629509512021

出版商:Taylor&Francis Group    

年代:1995

数据来源: Taylor