Association of dominant somatotype of men with body structure, function during exercise, and nutritional assessment

This study examined the hypothesis that somatotype determines body structur e, functional responses at peak exercise, and nutritional status of 63 men ages 18-40 years who lived under controlled conditions. Data were grouped b y dominant somatotype to emphasize differences in body types. Dominant ecto morphs (n = 19) had less (P < 0.05) body weight, fat weight, and percent bo dy fat than endomorphs (n = 14) and mesomorphs (n = 30). Fat-free weight (F FW), total body potassium (TBK), and body cell mass (BCM), normalized for s tature, were lower (P < 0.05) in the ectomorphs than in the endomorphs and mesomorphs. Comparisons between measured and predicted FFW and TBK showed t hat only the ectomorphs had less (P < 0.05) FFW and TBK than expected. Alth ough all groups had the same peak power output, the ectomorphs had differen t functional responses during peak exercise. Ectomorphs had the greatest re spiratory exchange ratio (P < 0.05), ventilatory equivalent for oxygen, and end-exercise plasma lactate concentrations (P < 0.05), and lowest peak oxy gen uptake (L/min; P < 0.05). Nutrient intakes and blood biochemical marker s of nutritional status were within the range of normal values in all group s. Correlations between measures of body structure, function, and nutrition al status and dominant somatotype components were calculated after controll ing for the effects of the other two somatotype components. Partial correla tions were variable, with significant correlations ranging from -0.30 to 0. 87. These data indicate that ectomorphs, as compared to endomorphs and meso morphs, have deficits in FFW and BCM which are associated with differences in functional capacity. (C) 2000 Wiley-Liss, Inc.(dagger)