Abstract

The present study was undertaken to investigate energy balance in professional male breath-hold divers in Tsushima Island, Japan. In 4 divers, rectal (Tre) and mean skin (Tsk) temperatures and rate of O2 consumption (VO2) were measured during diving work in summer (27 degree C water) and winter (14 degress C water). Thermal insulation and energy costs of diving work were estimated. In summer, comparisons were made of subjects clad either in wet suits (protected) or in swimming trunks (unprotected), and in winter, they wore wet suits. The average Tre in unprotected divers decreased to 36.4 +/0.2 degree C at the end of 1-h diving work, but in protected divers it dereased to 37.2 +/- 0.3 degree C in 2 h in summer and to 36.9 +/- 0.1 degree C in 1.5 h in winter. The average Tsk of unprotected divers decreased to 28.0 +/- 0.6 degree C in summer and that of protected divers decreased to 32.9 +/- 0.5 degree C in summer and 28.0 +/- 0.3 degree C in winter. Average VO2 increased 190 in unprotected divers in summer, but in protected divers it rose 120 in summer and 110 in winter. Total daily thermal cost of diving work was estimated to be 425 kcal/m2 in summer (276 min work) and 482 kcal/m2 in winter (240 min work). Verf.-Referat