摘要:

The nature, causes and treatment of exercise-induced bronchospasm (E.I.B.) are reviewed. The condition is common, particularly in children. The spasm affects mainly the large airways; it appears a few minutes after effort, peaks in 10 – 15 minutes, and commonly resolves spontaneously in 40 – 60 minutes. The origin is probably multifactorial, with reflex stimulation of tracheal receptors, altered sympathetic neural discharge, prostaglandins and mast-cell sensitization being involved on different occasions. Effective treatments are equally varied, including selective β agonists, theophylline and cromolyn glycate. For the sports physician, the best current approach seems the use of the Cromolyn drugs about one hour prior to competition.

ISSN:0025-7990    

出版商:OVID    

年代:1977

数据来源: OVID

摘要:

The possible causes of delayed muscle soreness which occur 24 to 48 hr after exercise were examined from three different approaches, each designed to test an existing hypothesis. Surface electromyograms were used to evaluate the muscle spasm theory; the possibility of actual muscle cell damage was monitored by the presence of myoglobinuria, while the ratio of hydroxyproline/creatinine (OHP/Cr) in 24 hr urine collection was used as a marker for connective tissue involvement. In the first study, although all volunteers developed muscle soreness 24 and 48 hr after exercise, no change in the EMG activity of the sore muscles was observed. Myoglobin excretion was found in 88% of the subjects who developed soreness. However, in a second study, 92% of the subjects who performed both moderate and heavy exercise but did not develop muscle soreness had myoglobinuria. In contrast, during a third experiment subjects on gelatin-free diets showed an increase (P < .1) in the OHP/Cr between control (.020 ± .001) and 48 hr post-exercise (.022 ± .001, X ± SE). Soreness resulted in all cases. When the OHP/Cr value is taken for the day of maximal soreness, the post-exercise mean increases to .024 ± .001 and the level of significance rises (P < .005). These observations support the concept that exercise induced soreness may be related to disruption of the connective tissue elements in the muscle and/or their attachments.

ISSN:0025-7990    

出版商:OVID    

年代:1977

数据来源: OVID

ISSN:0025-7990    

出版商:OVID    

年代:1977

数据来源: OVID

摘要:

Forty-seven active boys and girls, 7 to 12 years of age, underwent a comprehensive medical and physical evaluation in order to assess their prevalence of single and multiple coronary heart disease risk factors subject received a densiometric determination of body composition, blood lipid analysis, pulmonary function and a physical work capacity test to assess their peak oxygen consumption (Vo2max). Obesity (> 25% fat), elevated triglycerides (< 100 mg %) and the presence of Type IV hyperlipoproteinemia appear to be the more predominant risk factors. Twenty-nine (62%) of the children had at least one risk factor. Of these, seventeen had two or more risk factors with one subject having as many as five risk factors.

ISSN:0025-7990    

出版商:OVID    

年代:1977

数据来源: OVID

摘要:

Members of Swedish national teams in track and field events (sprinting and jumping), downhill skiing, race walking, orienteering, and a group of sedentary men were studied to examine the relationship between muscle fiber characteristics in needle biopsy samples from m. vastus lateralis and muscle strength measured as peak torque during isokinetic knee extensions. In comparison with the sedentary group the following differences were found: a) percentage fast twitch fibers was lower in the endurance athletes, b) fast to slow twitch muscle fiber area ratio was higher in the track athletes, c) track athletes and downhill skiers attained higher peak torque values at all angular velocities examined. The track athletes had, however, higher torque values at the fastest angular velocity as compared to the downhill skiers, whereas there was no difference under isometric conditions. The proportion of fast twitch fibers was related to torque produced, especially at high motion velocity. The training also appeared to affect the force-velocity relationship.

ISSN:0025-7990    

出版商:OVID    

年代:1977

数据来源: OVID

摘要:

Eighty-seven male inmates from a state prison and 70 inmates from a county jail volunteered as subjects. The subjects, age 20 to 35 yrs, were assigned randomly into a control or exercise group. Their Vo2max and treadmill performance values were determined before and after a 20 week jogging program. Training intensity was between 85 and 90 percent of maximum heart rate and involved workouts 3 days/ week for 15, 30, or 45-min duration at the state prison and for 30-min 1, 3, or 5 days/week at the country jail. Cardiorespiratory fitness improved in direct proportion to frequency and duration of training. Injury, occurred in 22%, 24% and 54% of the 15, 30, and 45-min duration groups and in 0%, 12%, and 39% of the 1, 3, and 5-day/week groups, respectively. Attrition resulting from injury occurred in 0%, 0%, and 17% and in 0%, 4%, and 6% of the same respective groups. Attrition due to lack of interest was similar for all training groups (25%), but was significantly lower in the control groups (10%). Although the results showed a greater increase in cardiorespiratory fitness for the 45-min duration and 5-day/week groups, these programs are not recommended for beginning joggers because of the significantly greater percent of injuries.

ISSN:0025-7990    

出版商:OVID    

年代:1977

数据来源: OVID

摘要:

The purpose of the investigation was to explore the validity of using timed distance runs as predictors of cardiorespiratory fitness in young untrained children. Maximal oxygen consumption and performance in runs of 549, 1207, and 1609 meters (600 yards, 3/4 mile, and 1 mile) were compared in 38 children eight years of age. Males were found to exceed females on Vo2max and possessed significantly faster times in the 1207 and 1609 meter runs. The females exhibited greater six-site skin-fold totals. The 1609 meter run proved to be the best predictor of Vo2max (ml/kg) in males. However, none of the three distances was acceptable for females.

ISSN:0025-7990    

出版商:OVID    

年代:1977

数据来源: OVID

摘要:

The purpose of this study was to compare the oxygen cost of running as it relates to speed of running among the following four groups: trained male distance runners, trained female distance runners, untrained but active men and women. Each subject was given a series of treadmill tests during which Vo2was measured at submaximal work loads. The linear regression equation was utilized to compute the relationship between Vo2and running speed for each group. The results indicated that the rate of increase in Vo2for a given increase in running speed could be represented as a straight line and was the same for all groups (P > .05). The trained male runners had a significantly lower Vo2(P < .05) than those of the other three groups at any measured speed. The trained females and untrained males had significantly lower Vo2s than the untrained females (P < .05) at any of the given range of speeds. No significant differences were observed between the untrained men and trained women (P > .05). It was concluded that-there were differences in the oxygen cost of running not only between the trained and untrained groups but also between males and females.

ISSN:0025-7990    

出版商:OVID    

年代:1977

数据来源: OVID

ISSN:0025-7990    

出版商:OVID    

年代:1977

数据来源: OVID

ISSN:0025-7990    

出版商:OVID    

年代:1977

数据来源: OVID