Changes in thermal insulation during underwater exercise in Korean female wet-suit divers

Abstract

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)

Thermal Insulation and Body Temperature Wearing a Thermal Swimsuit during Water Immersion

“…The I suit of the TSS calculated in the present study was significantly lower than that of wetsuits during immersion at rest reported in previous studies (Yeon et al, 1987;Iwamoto et al, 1990). Several studies reported that exercise in water decreases I suit because of water leakage (Wolff et al, 1985), however even the I suit values of wetsuits during water exercise calculated in those studies were significantly higher than those of the TSS condition during immersion at rest in the present study (Yeon et al, 1987;Kang et al, 1983;Shiraki et al, 1986;Arieli et al, 1995).…”

“…Several studies reported that exercise in water decreases I suit because of water leakage (Wolff et al, 1985), however even the I suit values of wetsuits during water exercise calculated in those studies were significantly higher than those of the TSS condition during immersion at rest in the present study (Yeon et al, 1987;Kang et al, 1983;Shiraki et al, 1986;Arieli et al, 1995). These data suggest that the TSS in the present study had significantly lower I suit than any other wetsuits in those previous studies.…”

“…Wearing an additional layer of insulation on the skin surface is a convenient means to reduce convective heat loss without increasing exercise intensity. Several studies have examined the effects of wetsuits (Wolff et al, 1985;Cotter et al, 1995;Yeon et al, 1987;Arieli et al, 1997;Kang et al, 1983). Some reported that wetsuits do not provide adequate thermal protection to maintain the core temperature in cool or cold-water (14-27°C) (Arieli et al, 1997;Shiraki et al, 1986).…”

“…However, the absolute value of I suit appeared to be affected by the experimental environment, subject gender, duration of immersion and calculation method. For that reason, the proportions of I suit to I total were compared for the TSS used in the present study and wetsuits used in previous studies (Yeon et al, 1987;Kang et al, 1983;Shiraki et al, 1986;Arieli et al, 1995;Iwamoto et al, 1990). Although 54-69% of I total were reported for wetsuits in previous studies, a mere 26.5 and 28.2% of I total were provided by the TSS in the present study at T w of 26 and 29°C, respectively.…”

Thermal responses for men with different fat compositions during immersion in cold water at two depths: prediction versus observation

“…Thus the revised muscle blood Xow rates in the CTM simulation, 5.0 l/min per 100 ml tissue, seem physiologically reasonable and the adjusted predicted T c consistent with observations. Exercise substantially lowers body insulation during cold immersion, probably by increasing muscle blood Xow (Sloan and Keatinge 1973;Yeon et al 1987). The contribution from cooled limb blood Xow to a decrease in T c has also been observed during cold-water immersion where blood Xow to the limbs was occluded (Mittleman and Mekjavic 1988).…”