The effect of exercise intensity on the post-exercise esophageal temperature response.

On 2 separate days, nine volunteers aged 23.8 (2.0) years performed 15-min bouts of treadmill running in a temperature-controlled chamber at 29 degrees C at a power output that elicited either 70% (moderate) or 93% (intense) of maximum oxygen consumption. Exercise was followed by a 45-min recovery period. End-exercise esophageal temperature (Tes) was elevated by 0.97 degrees C and 2.17 degrees C above baseline for the moderate and intense exercise trials, respectively. Post-exercise Tes achieved a sustained elevated value of 0.38 degrees C and 0.79 degrees C within 15 min of exercise cessation. Systolic blood pressure (SBP) for both exercise trials became hypotensive for the full recovery period, with the magnitude of the reduction being greater for the intense exercise (P < 0.05). Diastolic blood pressure (DBP) was unaffected by exercise intensity and values were lower than baseline between 15 min and 30 min post-exercise (P < 0.05). Mean arterial pressure (MAP) was reduced from baseline for both exercise trials, with intense exercise showing a greater decrement (P < 0.05). It was shown that the increase in the post-exercise hypotensive response, induced by exercise of increasing intensity, was paralleled by an increase in the magnitude of the post-exercise elevation in Tes (i.e., a difference of 0.41 degrees C between conditions).