Key points are not available for this paper at this time.
Output (Qsweat) and lactate concentration ( Lsweat) in frontal sweat and blood lactate concentration ( Lblood) were monitored in three male volunteers: one sedentary (S), one fit (F), and one very fit (VF). Measurements were made under three sweating conditions: 1) heat exposure to infrared radiation (IR) at rest for 25 min at 45 degrees C; 2) bicycle exercise at constant relative maximal aerobic power (87 +/- 2% MAP) for 25 min (Cst EX) at 23 degrees C; and 3) bicycle exercise at increasing work loads (from 60-95% MAP) in four or five successive 5-min steps (Incr EX) at 23 degrees C. Comparison of these data showed that under the above three conditions 1) Qsweat of S was lower than that of F and VF; and 2) changes in Lsweat were different: in IR and Cst EX, Lblood remained constant, and Lsweat decreased with heat load duration similarly in the three subjects (the slopes of the two curves were not significantly different); at Incr Ex, Lblood increased and Lsweat remained constant in S, F, and VF (21.71 +/- 0.85, 16.75 +/- 0.99, 12.83 +/- 0.45 (SE) mM, respectively). It was suggested that the high Lblood and increased adrenergic stimulation observed in Incr Ex could act on Lsweat in relation to the physical fitness level.
Fellmann et al. (Tue,) studied this question.