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 (V˙O_2max). One week later subjects exercised for 36 min on the same ergometer at approximately 65% V˙O_2max while temperatures at the rectum (T _re) and esophagus (T _es) were simultaneously measured. The V˙O_2max (l · 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)°C] was significantly higher than T _es 38.02 (0.12)°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°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. Accepted: 3 November 1997