Abstract

The purpose of this study was to determine if training in a cool (23 degrees C) environment would alter the potential for mortality or for tissue damage (as indicated by serum transaminase concentrations) during a work-heat tolerance test (WHTT) to exhaustion. 29 male Sprague-Dawley rats were trained (T) on a motorized treadmill for 6 wk, while 34 control animals of similar weight remained sedentary (S). Tissue damage among survivors 24 h following the WHTT and percent mortality were the same in both groups; however, T survivors 1) continued the test 44 longer, 2) performed significantly more work, and 3) sustained a 120 larger thermal load than S survivors. Mortality first occurred at a range in Tc of 40.6-41.0 degrees C in the S group compared with a range of 41.6-42.0 degrees C in the T group. Thus endurance T rats can run longer in the heat, sustain greater thermal loads, and are less susceptible to work-induced thermal fatality than S rats. Verf.-Referat