摘要:

The relationship between physical and psychologic stress, immune function, and upper respiratory tract infection (URTI) is reviewed in this article. There are relatively few studies that have explored this relationship. Of seven studies currently published, five are epidemiologic in design (two prospective and three retrospective), and only two used a randomized, controlled experimental design. In general, these studies support the concept that, although risk of URTI may decrease below that of a sedentary individual when engaging in moderate exercise training, risk may be elevated during periods of excessive amounts of exercise. Risk of URTI in athletes appears to be especially high during the 1‐or 2‐week period following marathon‐type race events. Among runners varying widely in training habit, the risk for URTI is slightly elevated for those runners with the highest training mileage only when several confounding factors are controlled for. This interpretation is consistent with experimental evidence from both human and animal studies.

ISSN:1057-8315    

DOI:10.1080/15438629309511960

出版商:Taylor&Francis Group    

年代:1993

数据来源: Taylor

摘要:

A total of 231 weightlifters and powerlifters were asked in an anonymous poll whether they had taken anabolic steroids (AS) for longer than 3 months. A sample of blood was taken from the 17 athletes (7.4%) who answered positively and agreed to cytogenetic analysis of peripheral lymphocytes in order to identify the possible genotoxic risk, and the results were compared with a reference group of 45 blood donors. On the basis of cytogenetic analysis, the increased quantity of chromosome aberrations in peripheral lymphocytes was found to be 2.6% in comparison with the level of 1.3% in a reference group. These results were also verified by the distribution of aberrant cells in cultures of lymphocytes that were analyzed. These results indicated an increased risk of genotoxic exposure of these athletes, which might cause an increase in malignant diseases.

ISSN:1057-8315    

DOI:10.1080/15438629309511961

出版商:Taylor&Francis Group    

年代:1993

数据来源: Taylor

摘要:

Nineteen competitive male endurance athletes (11 runners and 8 duathletes/triathletes) were compared to determine what effects cross‐training might have on running performance. Subjects were evaluated for a difference in maximal oxygen consumption (VO2max), running economy, running mechanics, and best 10 km performance time. The runners exhibited a significantly greater weekly training run mileage, a lower number of weekly training hours, a longer running step length, and a faster 10 km performance time compared with the multisport athletes (p≤0.05). In addition, the runners exhibited a better running economy, requiring 6.20%, 6.13%, and 6.78% less utilization of VO2maxat three standard velocities of submaximal treadmill running. These results suggest that enhancement of running performance might be best obtained by running‐specific training activity rather than from cross‐training methods.

ISSN:1057-8315    

DOI:10.1080/15438629309511962

出版商:Taylor&Francis Group    

年代:1993

数据来源: Taylor

摘要:

Seat pain is common among amateur bicyclists, who often self‐treat seat pain with skin creams. This research evaluates the efficacy of two commonly used creams, compared with a placebo, for preventing bicycle‐related seat pain. Studied were 188 adults participating in a 500 mile, week‐long amateur bicycle trip. Participants were randomly allocated to receive 0.5% hydrocortisone cream, 10% trolamine salicylate cream, or a nonmedicated placebo cream, in a double‐blind fashion. Each cyclist applied cream to his seat area skin twice daily. After the ride, cyclists were evaluated to determine severity of their seat pain and presence of skin breakdown. The data were analyzed to determine if these outcomes differed among the three groups. Overall, 84.9% of the participants experienced seat pain and 6.9% had seat area skin breakdown, but there were no significant differences among the three cream groups. These results show that hydrocortisone (0.5%) or trolamine salicylate (10%) creams are no more effective than placebo for preventing bicycle‐related seat pain.

ISSN:1057-8315    

DOI:10.1080/15438629309511963

出版商:Taylor&Francis Group    

年代:1993

数据来源: Taylor

摘要:

A method of testing endurance capacity and physical fitness (40‐minute test) based on control of the test work rate by a defined heart rate (clamped heart rate [CHR] test) is proposed. This test was used on 26 men and 19 women with sedentary occupations, about half of whom had regular unorganized sporting activity. A subject's physiologic reaction to a heart rate adjusted work rate and, concomitantly, endurance performance and physical fitness was assessed on the basis of the time course of a changing intensity of work rate necessary to maintain a CHR. Auxiliary indices of the test, some of them marking a significant difference between subgroups with different levels of physical fitness, were calculated. Average power output related to weight and to the utilized portion of circulation capacity was determined as the basic criterion of physical fitness. A comparison between the indices revealed that the better a person's physical fitness, the less frequent was a reduction in work rate necessary to maintain the CHR and the more stable was the person's reaction to the initial work rate. With age, the number of changes in work rate declined but the decrease in work rate intensity during the whole test was greater. Because work rate intensity decreased during the CHR test, the test is less taxing and thus also more suitable for unfit subjects. If the heart rate is clamped within a required level throughout the test and the duration of the test is shortened by the attending physician, the test is also applicable for the diagnostic evaluation or rehabilitation of a cardiac or otherwise disabled patient.

ISSN:1057-8315    

DOI:10.1080/15438629309511964

出版商:Taylor&Francis Group    

年代:1993

数据来源: Taylor

摘要:

The purpose of this study was to examine the growth pattern and sexual maturation rate of identical triplets, one of whom was a highly ranked competitive gymnast who subsequently retired from the sport 8 months into the study. Baseline measurements were conducted when the sisters were 11.5 years of age. They were then repeated 18 and 24 months later. The gymnast had been in training and competition for 5 years at the time of the initial measurements. At the time of baseline measurements on the three girls, the gymnast's height fell between that of her two sisters, but at the 18‐month measurement, which was 10 months after she retired, she had grown 10.2 cm, compared with 4.9 and 5.8 cm for her sisters. Likewise, during this same time frame, she gained 13.6 kg, while sister 1 gained 10.9 kg and sister 2 gained 5.9 kg. At baseline, the gymnast was at the 68th percentile of weight for age, and her sisters were at the 83rd and 95th percentiles, respectively. Eighteen months later, the gymnast had increased to the 83rd percentile, while sister 2 decreased to the 70th and sister 3 remained at the 95th. Furthermore, during this time, the body fat of the gymnast increased from 13.6 to 18%, and her waist to hip ratio decreased by 0.07, indicating an increase in fat deposition in the hip region. Onset of menarche occurred at 12 years, 10 months in the gymnast, and at 11 years, 3 months and 11 years 9 months in sisters 1 and2, respectively. Taken together, these data indicate that the gymnast may have undergone mild growth retardation during her years in training and competition, followed by catch‐up growth in the 10 months after she retired from the sport.

ISSN:1057-8315    

DOI:10.1080/15438629309511965

出版商:Taylor&Francis Group    

年代:1993

数据来源: Taylor

摘要:

It has been shown that exercise has a positive influence on the course of patients with coronary heart disease. However, the effect of exercise in patients with coronary heart disease and noninsulin‐dependent diabetes mellitus (NIDDM) is unknown. The study involved 30 men 47 to 66 years old with coronary heart disease and NIDDM; their tolerance for exercise increased, the number of angina episodes decreased during daily activity, and there was a reduction in resting glycemia. A schedule of an exercise session lasting 5 minutes six times a week, which was increased by 5 minutes after every 7 to 10 training sessions, is completely safe for use in outpatient rehabilitation of these patients.

ISSN:1057-8315    

DOI:10.1080/15438629309511966

出版商:Taylor&Francis Group    

年代:1993

数据来源: Taylor

摘要:

The impact of anabolic steroid (AS) use on left ventricular function was investigated in three groups: nine experienced body builders who self‐administered a variety of AS (mean dose/week, 576.8 mg, 200 to 1300% of the highest recommended medical dose), five experienced body builders not using AS but similarly trained, and six sedentary controls (mean age, 29.0±4.5 years). Maximal incremental treadmill tests and leg press exercise consisting of three sets of 15 repetitions at 70% of 1 repetition maximum were conducted in randomized order and separated by at least 24 hours. Aortic blood flow acceleration and velocity were measured by Doppler echocardiography at rest, immediately following maximal exercise on the treadmill, and during leg press exercise. Group comparisons showed no differences between groups for any of these variables. Resting serum creatine kinase (CK) activity was also evaluated for detection of possible cardiac cell damage in each group. AS users had higher total CK (1235.2±903.1 mU/ml) than nonusers (294.8±316.8 mU/ml) and controls (175.8±132.1 mU/ml). However, there was no difference between groups for elevation of the CK‐MB isoenzyme percent increase. These data indicate that anabolic steroid use does not affect left ventricular function or cause cardiac cell damage in body builders.

ISSN:1057-8315    

DOI:10.1080/15438629309511967

出版商:Taylor&Francis Group    

年代:1993

数据来源: Taylor

摘要:

The purpose of this study was to assess the effect of variation in the order of four different isokinetic velocity exercise protocols on muscle torque production. Twenty‐two subjects were randomly assigned to four exercise trials, each containing an isokinetic exercise session involving the dominant knee extensor and flexor. Each trial consisted of performing two sets of 10 repetitions at velocities of 30°, 90°, 150°, and 210°per second in varying order. Peak torque (Nm), average peak torque (Nm), and average torque (Nm) were used to make comparisons between the four protocols. Univariate analysis showed no significant effect (p>0.05) of varying the order of isokinetic velocity of muscle contraction in the four protocols described for any of the three torque measurements. It was concluded that varying the pattern of isokinetic velocity at which a specific torque is developed does not interfere with general or specific torque at a particular velocity of contraction.

ISSN:1057-8315    

DOI:10.1080/15438629309511968

出版商:Taylor&Francis Group    

年代:1993

数据来源: Taylor

ISSN:1057-8315    

DOI:10.1080/15438629309511969

出版商:Taylor&Francis Group    

年代:1993

数据来源: Taylor