Muscle temperature transients and post-exercise esophageal temperature elevation.

Abstract

The primary purpose of this research was to study esophageal temperature elevation and quadriceps and triceps intra-muscular temperature gradients during resting recovery from exercise. Eight physically active male participants and 24 +/- 4 years of age, rested in a buttocks supported upright posture for a 50 +/- 12.5 minutes in ambient conditions of 24.7 +/- 1.17°C and 24 +/- 4.6% relative humidity. Participants then performed a steady state cycle ergometry exercise at 70% VO2 max, until they reached until heat produced by exercise above metabolic rate accumulated to 1000 kJ. This was followed by 120 minutes of resting recovery. Active intra-muscular temperature was measured in the vastus medialis at four depths, with the tip of the probe being at 10 mm from the femur and deep femoral artery and the others sensor at 15, 30 and 45 mm from the tip of the probe. Pre-exercise resting esophageal temperature and quadriceps intra-muscular temperatures were 36.95 +/- 0.22°C (Tes), 36.31 +/- 0.39°C (Tmuq1), 36.10 +/- 0.50°C (Tmuq2), 35.75 +/- 0.84°C (Tmuq3) and 35.33 +/- 0.88°C (Tmuq4) respectively. Exercise resulted in a 0.94 +/- 0.32°C increase in esophageal temperature above pre-exercise resting values. End of exercise intra-muscular quadriceps temperatures were 38.81 +/- 0.42°C (T muq1), 38.61 +/- 0.60°C (Tmuq2), 38.13 +/- 0.75°C (Tmuq3) and 37.71 +/- 0.96°C (Tmuq4 ). Esophageal temperature remained significantly elevated from pre-exercise resting values for 10 minutes following exercise. These results indicate that post-exercise esophageal temperature elevation, following cycle ergometry exercise, is not dependent on a temperature gradient between esophageal temperature and deep muscle temperature from the previously active muscle. Further, a prolonged and sustained post-exercise esophageal temperature was not demonstrated following this cycle ergometry exercise.