Journal of Applied Physiology, Vol 62, Issue 3 1014-1019, Copyright © 1987 by American Physiological Society
Changes in thermal insulation during underwater exercise in Korean female wet-suit divers
D. S. Yeon, Y. S. Park, J. K. Choi, J. S. Kim, I. S. Lee, D. H. Kang, S. H. Lee, S. Y. Hong, D. W. Rennie and S. K. Hong
The present work was undertaken to examine the effect of wet suits on the
pattern of heat exchange during immersion in cold water. Four Korean women
divers wearing wet suits were immersed to the neck in water of critical
temperature (Tcw) while resting for 3 h or exercising (2-3 met on a bicycle
ergometer) for 2 h. During immersion both rectal (Tre) and skin
temperatures and O2 consumption (VO2) were measured, from which heat
production (M = 4.83 VO2), skin heat loss (Hsk = 0.92 M +/- heat store
change based on delta Tre), and thermal insulation were calculated. The
average Tcw of the subjects with wet suits was 16.5 +/- 1.2 degrees C (SE),
which was 12.3 degrees C lower than that of the same subjects with swim
suits (28.8 +/- 0.4 degrees C). During the 3rd h of immersion, Tre and mean
skin temperatures (Tsk) averaged 37.3 +/- 0.1 and 28.0 +/- 0.5 degrees C,
and skin heat loss per unit surface area 42.3 +/- 2.66 kcal X m-2 X h. The
calculated body insulation [Ibody = Tre - Tsk/Hsk] and the total shell
insulation [Itotal = (Tre - TW)/Hsk] were 0.23 +/- 0.02 and 0.5 +/- 0.04
degrees C X kcal-1 X m2 X h, respectively. During immersion exercise, both
Itotal and Ibody declined exponentially as the exercise intensity
increased. Surprisingly, the insulation due to wet suit (Isuit = Itotal -
Ibody) also decreased with exercise intensity, from 0.28 degrees C X kcal-1
X m2 X h at rest to 0.12 degrees C X kcal-1 X m2 X h at exercise levels of
2-3 met.(ABSTRACT TRUNCATED AT 250 WORDS)
