摘要:

&NA;Presented at the Symposium on the Thermal Effects of Exercise in the Heat at the 25th Annual Meeting of the American College of Sports Medicine, May 24‐27, 1978, Washington, D.C.ABSTRACTDRINKWATER, B.L. and S.M. HORVATH. Heat tolerance and aging.Med. Sci. Sports. Vol. 11, No. 1, pp. 49‐55, 1979. Although children and older adults appear more susceptible to heat stress, the mechanisms responsible for their lower tolerance are not fully understood. Many studies dealing with the effect of age on temperature regulation have concluded that an inadequate sweating response is primarily responsible for the low tolerance of children and the elderly to exercise in the heat. However, the dependence of core temperature on relative exercise intensity and sweat rate on absolute exercise intensity makes it difficult to avoid the confounding effects of exercise on thermoregulation when aerobic power (&OV0312;o2max) varies across age groups. When 38 non‐acclimatized females, ages 12 to 68 years, exercised at 30‐35% &OV0312;o2max in the heat, the degree of cardiovascular stability was the primary predictor of tolerance time. Age was not a significant predictor. However, it was evident that individuals at either end of the age continuum were more likely to be at risk. For children this risk was associated with the instability of an immature cardiovascular system; for older women, a marked decrement in aerobic power. Sweat rate added significantly to the prediction of tolerance time for all subjects regardless of age. Whether the decrease in responsiveness of sweating noted for some older individuals is an age related change or a reflection of their lower fitness levels is not known.THERMOREGULATION, AGING, HEAT TOLERANCE, HEAT STRESS

ISSN:0025-7990    

出版商:OVID    

年代:1979

数据来源: OVID

摘要:

&NA;Presented at the Symposium on the Thermal Effects of Exercise in the Heat at the 25th Annual Meeting of the American College of Sports Medicine, May 24‐27, 1978, Washington, D.C.ABSTRACTGISOLFI, CARL V. and JUDITH S. COHEN. Relationships among training, heat acclimation, and heat tolerance in men and women: the controversy revisited.Med. Sci. Sports. Vol. 11, No. 1, pp. 56‐59, 1979. For more than a decade there has been a controversy over the beneficial effects of physical training in a cool environment on exercise‐heat tolerance. The issues include (a) inadequate controls regarding the physical characteristics of subjects, (b) marked variability in the conditions of the standard heat tolerance tests and (c) differences in the intensity and duration of the training programs employed. Intense training in a cool environment cannot serve as a substitute for exercise in the heat if acclimation is desired within a 2 week period. However, a substantial improvement (50%) in heat tolerance can be derived from 8‐11 weeks of training under temperate conditions (21°C) and thermal equilibrium can be maintained for at least 4 hours during mild work (200 W/m2) in dry or wet heat by endurance runners. These adjustments occur in both men and women and appear to be independent of aerobic capacity. The key to improved thermal tolerance with training in a cool environment is maintenance of an elevated core temperature for a sufficient duration of time to produce an adaptive response.INTERVAL TRAINING, ENDURANCE TRAINING, HEAT‐ACCLIMATION, THERMAL TOLERANCE, WOMEN, MAXIMAL OXYGEN UPTAKE.

ISSN:0025-7990    

出版商:OVID    

年代:1979

数据来源: OVID

摘要:

&NA;Presented at the Symposium on the Thermal Effects of Exercise in the Heat at the 25th Annual Meeting of the American College of Sports Medicine, May 24‐27, 1978, Washington, D.C.ABSTRACTPANDOLF, KENT B. Effects of physical training and cardiorespiratory physical fitness on exercise‐heat tolerance: recent observations.Med. Sci. Sports. Vol. 11, No. 1, pp. 60‐65, 1979. Most authors agree that physical training in a cool environment improves tolerance to exercise in the heat and the rate of heat acclimatization, but the extent or degree of improvement remains controversial. The best improvement in heat tolerance for men is associated with intensive interval or continuous training at a training intensity greater than 50% of maximal oxygen uptake (&OV0312;o2max) for 8‐12 weeks; the &OV0312;o2max should be increased 15‐20%. Far less is known about the appropriate type, intensity and duration of endurance training associated with improved exercise‐heat tolerance in women. The major benefits of physical training appear to apply to both short term (<2 hrs) or long term (>2 hrs) exercise‐heat exposures for men. Generally, individuals with high &OV0312;o2max values (previously trained and endurance athletes) are at an advantage in the heat. Utilization of proper physical training appears to produce about 50% of the total adjustment resulting from heat acclimatization, while increased fitness is associated with greater retention of acclimatization in cool environments. Female athletes appear somewhat better able to tolerate exercise in hot environments than nonathletic females while differences between highly trained females and males do not appear as dramatic as once thought.HEAT ACCLIMATIZATION, EXERCISE‐HEAT TOLERANCE, PHYSICAL TRAINING, MAXIMAL OXYGEN UPTAKE, SEX DIFFERENCES, HEART RATE, RECTAL AND SKIN TEMPERATURES, HIGHLY TRAINED ATHLETES, PHYSICAL FITNESS, RETENTION OF ACCLIMATIZATION

ISSN:0025-7990    

出版商:OVID    

年代:1979

数据来源: OVID

摘要:

&NA;Presented at the Symposium on the Thermal Effects of Exercise in the Heat at the 25th Annual Meeting of the American College of Sports Medicine, May 24‐27, 1978, Washington, D.C.ABSTRACTHUBBARD, ROGER W. Effects of exercise in the heat on predisposition to heatstroke.Med. Sci. Sports. Vol. 11, No. 1, pp. 66‐71, 1979. This article reviews briefly the historical origins for both the cardiovascular and neural‐anhidrotic concepts of heatstroke pathophysiology. It describes how deemphasis of the role of anhidrosis as the primary cause of heatstroke has resulted in: (a) an increased acceptance of animal models for heatstroke research; (b) further evidence that rigid reliance on the classic heatstroke symptoms (coma, anhidrosis, and a fever over 106°F) can result in underdiagnosis; and (c) new research consistent with the hypothesis that exhaustive physical effort, by worsening circulatory collapse and metabolic acidosis predisposes tissue to hyperthermic injury and, as a result, substantially lowers the threshold for heatstroke injury and mortality. Thus, a new hypothesis combining the essential features of both direct thermal injury and cardiovascular origins of heatstroke pathophysiology may be necessary.EXERCISE, HEATSTROKE MODEL, SERUM TRANSAMINASES

ISSN:0025-7990    

出版商:OVID    

年代:1979

数据来源: OVID

ISSN:0025-7990    

出版商:OVID    

年代:1979

数据来源: OVID