ISSN:
1439-6327
Keywords:
Body temperature
;
Heat acclimation
;
Heart rate
;
Exercise
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary It has been reported that scores from a temperate-environment step test describe the heat-tolerance status of prior heatstroke patients (HP). This investigation evaluated the ability of this temperate-environment heat-tolerance test (HTT) to indicate altered heart rate (HR) and rectal temperature (T re )responses of HP, after 7 days of heat acclimation. On day 1, ten male HP (61 ± 7 days post-heatstroke) and five control subjects (C) bench-stepped (0.30 m high, 27 steps · min−1) for 15 min (25.8° C dry bulb, 16.2° C wet bulb). On days 2–8, subjects underwent heat acclimation (40.1° C dry bulb, 23.8°C wet bulb; treadmill, 90 min · day−1). Heat acclimation resulted in significant decreases in final HR (152±5 vs 130±3 beats·min−1 P〈0.025) and finalT re (38.62±0.11 vs 38.13±0.07°C,p 〈 0.01) in HP. One HP but no C was defined heat intolerant, exhibiting inability to adapt to daily exercise in the heat. On day 9, HP repeated HTT, exactly as performed on day 1; mean group HTT scores did not change (day 1=39±6; day 9=48±6,P〉0.05). All physical characteristics and physiological responses of HP (days 1, 2, 7, 9) were statistically similar (P〉0.05) to those of C. In contrast to heat-acclimation data, HTT scores (score ≤30) indicated that four HP were heat intolerant on day 1 and two HP were heat intolerant on day 9. It was concluded that HTT was not a substitute for lengthier tests of heat tolerance conducted in hot environments, because HTT scores (at 25.8°C did not reflect HR andT re responses (at 40.1° C) in 33% of heat-acclimated (e.g., heat-tolerant) HP. In addition, HTT scores did not validly discriminate between heat tolerant and heat-intolerant HP.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00839160
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