Responses of sweating and body temperature to sinusoidal exercise
in physically trained men.
Yamazaki, Fumio, Nobuharu Fujii, Ryoko Sone, Haruo Ikegami.
Institute of Health and Sport Sciences, University of Tsukuba,
Tsukuba, Ibaraki 305, Japan
APStracts 2:0443A, 1995.
The effect of physical training on the dynamic responses of sweating
to transient exercise is still controversial. We determined the phase
response and amplitude response (D) of sweating rate and body
temperature to sinusoidal exercise in physically trained and
untrained subjects. Eight trained male subjects (Trained Group) and
seven untrained male subjects (Untrained Group) exercised on a cycle
ergometer with a constant load for 30 min; for the next 28 min they
exercised with a sinusoidal load. The sinusoidal load variation
ranged from about 10% to 60% of VO2peak with a 4-min period. The
ambient temperature and the relative humidity during exercise were 25
degrees C and 35%, respectively. There was no difference between the
groups in the phase lags of esophageal temperature (Tes) and mean
skin temperature (Tsk), whereas those of sweating rate for the chest
[msw(chest)] and forearm [msw(forearm)] were significantly shorter in
the Trained Group (P<0.05). The D of Tes and Tsk per 1 W of
exercise load in the Trained Group was significantly smaller than
that in the Untrained Group (both, P<0.05), while there was no
difference between the groups in the D of msw(chest) and
msw(forearm). We conclude that subjects who have undergone long-term
physical training show prompter dynamic characteristics of sweating
response compared to untrained subjects and have a higher capacity to
maintain constant body temperature during exercise at transient load.
Received 9 January 1995; accepted in final form 29 September
1995.
APS Manuscript Number A18-5.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 6 November 95