RATINGS OF PERCEIVED EXERTION AND AFFECT IN HOT AND COOL ENVIRONMENTS

The effects of hot and cool environments on perceptual and physiologic al responses during steady-state exercise were examined in men (n = 14 ) performing 30 min of constant exercise (cycle ergometry) at a percei ved exertion of ''somewhat hard''. Subjects exercised at the same abso lute exercise intensity in hot (40-degrees-C), neutral (24-degrees-C), and cool (8-degrees-C) conditions. Data were collected for differenti al ratings of perceived exertion (RPE), affect, thermal sensation, mea n skin (T(sk)BAR) and rectal temperatures (T(re)), and cardiac frequen cy (f(c)). The subjects completed the hot exposure with an average T(s k)BAR of 37.5-degrees-C (SEM 0.11), while the neutral and cool conditi ons produced values of 33.8 (SEM 0.09) and 28.2-degrees-C (SEM 0.30), respectively. The T(sk) was significantly higher in the hot than the n eutral and cool conditions throughout exercise (P<0.05). The f(c) was significantly lower in the cool than in the other conditions (P < 0.05 ), and the subjects completed the hot exposure with a mean f(c) more t han 20 beats . min-1 greater than observed in the other conditions. Th e subjects felt worse (lower affect) in the heat throughout exercise ( P<0.05). Overall RPE was significantly lower in the cool than in the h eat, while chest RPE scores for the cool and hot conditions were displ aced vertically by approximately two points. Subjects perceived work t o be harder, felt worse, and experienced greater thermal sensation in the hot condition, compared with the neutral and cool conditions. Chan ges in cutaneous vasomotor tone and heat-induced influences on the che st may have accounted for the RPE changes observed in the heat.