Rectal and esophageal temperatures during upper- and lower-body exercise.

This study investigated the question: is core temperature measurement influenced by whether exercise involves predominantly upper- or lower-body musculature? Healthy men were allocated to three groups: treadmill ergometry (T) n = 4, cycle ergometry (C) n = 6 and arm crank ergometry (AC) n = 5. Subjects underwent an incremental exercise test to exhaustion on an exercise-specific ergometer to determine maximum/peak oxygen consumption (VO2max). One week later subjects exercised for 36 min on the same ergometer at approximately 65% VO2max while temperatures at the rectum (T(re)) and esophagus (T(es)) were simultaneously measured. The VO2max (1 x min(-1)) for groups T [4.76 (0.50)] and C [4.35 (0.30)] was significantly higher than that for the AC group [2.61 (0.24)]. At rest, T(re) was significantly higher than T(es) in all groups (P < 0.05). At the end of submaximal exercise in the C group, T(re) [38.32 (0.11) degrees C] was significantly higher than T(es) [38.02 (0.12) degrees C, P < 0.05]. No significant differences between T(re) and T(es) at the end of exercise were noted for AC and T groups. The temperature difference (T(diff)) between T(re) and T(es) was dissimilar at rest in the three groups; however, by the end of exercise T(diff) was approximately 0.2 degrees C for each of the groups, suggesting that at the end of steady-state exercise T(re) can validly be used to estimate core temperature.