RESUMO
BACKGROUND: Neuromuscular fitness can be influenced at puberty by a steroid hormones, such as testosterone (TRT) and estradiol (EST). However, more information is needed to assess the reliability between the discriminatory power of biological age (BA) markers with the discriminatory power of TRT and EST in relation to muscle strength in young athletes who are at puberty. The aim of this paper was to analyze BA, TRT and EST as discriminating factors of upper limb (ULS) and lower (LLS) strength levels in young athletes. METHODS: The sample of 81 young athletes (54.4% female and 45.6% male; age: 11.4±1.08). Hormones were analyzed by chemiluminescence, BA markers by anthropometric variables and body composition by tetrapolar bioimpedance. ULS was verified by the medicineball launch test and LLS by the countermovement jump test on a force platform. RESULTS: EST was reliable for discriminating ULS (P<0.05) and LLS (P<0.05) in females. TRT showed reliability in discriminating ULS (P<0.05) and LLS (P<0.05) in males. BA was significant in discriminating ULS (P<0.0001) in females and ULS (P=0.002) and LLS (P<0.0001) in males. BA showed significant reliability with hormonal analyzes (P<0.05). CONCLUSIONS: That hormonal concentrations are reliable in discriminating ULS and LLS of young athletes of both sexes. BA was shown to be effective in discriminating ULS (in both sexes) and LLS (in males). BA showed significant reliability with hormonal analyzes (ULS and LLS in male sex; LLS for female sex).