The triathlon combines three resistance sport disciplines and requires physical characteristics to optimize the performance of each segment. The aim of this study was to determine the morphological profile of the triathlete. A retrospective analysis was performed on 153 protocols including: weight, height, perimeters, diameters, lengths, and skinfolds. The male and female samples were divided into senior and junior, and senior into first and second ranking levels.

The somatotype was ecto-mesomorph, except for junior females, for which it was central. The senior category had a fat percentage (Withers, 1987) lower than the junior, men 7.4 vs. 8.5; females 13.9 vs. 16.8; and level 1 compared to level 2 in females, 11.8 vs. 16.2. Muscle mass (Lee, 2000) for the senior was higher than for the junior, in males in kilograms (32.1 vs. 30.9), and females in percentage (42.8 vs. 41); level 1 female compared to 2 (44.2 vs. 41.2). Muscle cross-section areas (Heysmfield, 1982) in arm and thigh were higher in senior male than in junior male; and for senior female in the thigh it was higher in level 1 than in level 2. The indices were in the middle range, the senior male having a brachial index greater than the junior male.

Males only reachedthe senior phase in the upper body musculoskeletal development; while females reach it in the junior phase. The performance in the senior females is marked by greater age and lower fat levels. Triathletes should have a weight with low percentage of body fat and a musculoskeletal component in the medium range.