Thermal Responses During Extended Water Immersion: Comparisons of Rest and Exercise, and Levels of Immersion

Abstract : Fourteen male volunteers participated in Phase 1 of the project. Prior to experimental tests, subjects completed a medical evaluation and were cleared for testing by a physician, and performed body composition and maximal aerobic power tests on both a treadmill and bicycle ergometer. Mean age, height and weight of the group were 25.0 yr, 176.0 cm and 76.6 kg, respectively. Three groups of subjects were formed on the basis of body composition analysis. The mean % body fat values were 9.5 for the low-fat group (L, N=5), 14.8 for the moderate-fat group (A, N=5), and 19.6 for the high-fat group (H, N=4); maximal aerobic power on the treadmill and bicycle ergometer was 4.6 1/min and 3.98 l/ min for L , 4.31 1/min and 3.68 1/min for A and 4.32 1/min and 3.86 1/min for H respectively. Keywords: Immersion, Cold water, Esophageal temperature, Rectal temperature, Oxygen uptake, Ventilation, Volunteers, Prediction modeling, Environmental tolerance.