Thermoregulatory responses of paraplegic and able-bodied athletes at rest and during prolonged upper body exercise and passive recovery.

Abstract

The thermoregulatory responses of ten paraplegic (PA; T3/4-L4) and nine able-bodied (AB) upper body trained athletes were examined at rest and during prolonged arm-cranking exercise and passive recovery. Exercise was performed for 90 min at 80% peak heart rate, and at 21.5 (1.7) degrees C and 47.0 (7.8)% relative humidity on a Monark cycle ergometer (Ergomedic 814E) adapted for arm exercise. Mean peak oxygen uptake values for the PA and AB athlete groups were 2.12 (0.41) min(-1) and 3.19 (0.38) l x min(-1), respectively (P<0.05). At rest, there was no difference in aural temperature between groups [36.2 (0.4) degrees C for both groups]. However, upper body skin temperatures for the PA athletes were approximately 1.0 degrees C warmer than for the AB athletes, whereas lower body skin temperatures were cooler than those for the AB athletes (1.3 degrees C and 2.7 degrees C for the thigh and calf, respectively). Upper and lower body skin temperatures for the AB athletes were similar. During exercise, blood lactate peaked after 15 min of exercise for both groups [3.33 (1.26) mmol x l(-1) and 4.30 (1.03) mmol x l(-1) for the PA and AB athletes, respectively, P<0.05] and decreased throughout the remainder of the exercise period. Aural temperature increased by 0.7 (0.5) degrees C and 0.6 (0.4) degrees C for the AB and PA athletes, respectively. Calf skin temperature for the PA athletes increased during exercise by 1.4 (2.8) degrees C (P<0.05), whereas a decrease of 0.8 (2.0) degrees C (P<0.05) was observed for the AB athletes. During the first 20 min of recovery from exercise, the calf skin temperature of the AB athletes decreased further [-2.6 (1.3) degrees C; P<0.05]. Weight losses and changes in plasma volume were similar for both groups [0.7 (0.5) kg and 0.7 (0.4) kg; 5.4 (4.9)% and 9.7 (6.2)% for the PA and AB athletes, respectively]. In conclusion, the results of this study suggest that the PA athletes exhibit different thermoregulatory responses at rest and during exercise and passive recovery to those of upper body trained AB athletes. Despite this, during 90 min of arm-crank exercise in a cool environment, the PA athletes appeared to be at no greater thermal risk than the AB athletes.