The purpose of this study was to conduct an anthropometric assessment of both sides of the body in adolescent swimmers. The sample comprised 83 swimmers (52 males and 31 females) with an average age of 15.21±1.90 years. Their anthropometric values were studied in relation to the variables of age, sex, years of training, swimming stroke (simultaneous or alternating), dominant side, non-dominant side, breathing side, weight and height to determine whether any differences existed in the composition of each side of the swimmers bodies. Body composition was assessed using skinfolds (tricipital, subscapular, bicipital, iliac crest, supraspinal, abdominal, anterior thigh and anterior lower leg), lengths (upper arm, forearm, hand, thigh, lower leg and foot), perimeters (relaxed arm, flexed arm, forearm, wrist, thigh, lower leg and ankle) and diameters (wrist, hand, foot, malleolus, humerus and femur). Other values determined were fat mass, muscle mass, residual mass and bone mass (including percentages), sum of skinfolds and calculation of somatotype. The data obtained showed no statistically significant differences between the measures taken on each side of the swimmers bodies, even when they were analysed using the variables of years of training and swimming stroke. Continuous, intensive swimming during the growth stages does not cause body asymmetry in swimmers, even when the swimming stroke is alternating, thus supporting the thesis that swimming is a sport that works all muscles and provides a balanced body composition.

KEY WORDS: Anthropometry; Swimming; Body composition; Somatotype.