Background and Study Aim: Maladaptive changes and asymmetries represent a high risk of adolescent injury in judo practice. Another health risk in judo is the manipulation of body weight to compete in the tactically most advantageous weight category.
The aim of the study was the gender differences in body composition, upper limb muscle strength, upper and lower limb morphology in adolescent judo athletes. Material and Methods: Fifty-nine judo athletes participated in the study (39 boys and 20 girls); all were members of the Czech adolescent judo teams.
Using multi-frequency bio-impedance analysis, we monitored body height, body mass, body mass index, lean body mass, relative lean body mass, percentage of fat mass, bone mass, protein mass, total body water, segmental proportion of muscle mass, fat mass, phase angle and percentage differences between the upper and lower extremities. Muscle strength was measured using a calibrated hand dynamometer.
Results: The difference in the percentage of fat mass between boys and girls was significant (boys: 17.27 +/- 5.02%, girls: 23.38 +/- 4.28%, F = 22.48, p = 0.00, d = 1.31). The boys had a significantly higher proportion of muscle mass in upper and lower limbs compared with the girls (p0.05).
In the non-dominant limb, we detected a significant correlation between the phase angle and the level of muscle strength (boys: r = 0.64, p<0.01, girls: r = 0.61, p< 0.01). Conclusions: To reduce the risk of injury and negative impacts on the health of adolescent athletes, it is important to continuously monitor and correct optimal body composition concerning the targeted weight category of each athlete and the symmetrical proportion of active mass in particular segments.