Hormonal and inflammatory responses in prepubertal vs. pubertal male children following an acute free-weight resistance training session.

ABSTRACT

PURPOSE: Examine the acute hormonal and cytokine responses to free-weight resistance training in trained prepubertal and pubertal male children. METHODS: Prepubertal (n = 21; age 11.4 ± 1.1 years; Tanner I-II) and pubertal male children (n = 20; age 15.8 ± 0.7 years; Tanner III-V) conducted a moderate-intensity free-weight resistance training program to failure with venous blood sampling before (pre), immediately after (post) and during the recovery phase of the program (post-15,-30 min). Growth hormone (GH), insulin-like growth factor-I (IGF-I), cortisol, testosterone, IL-6, and TNF-α were analyzed in serum samples. Biological maturation was assessed according to the stages of the Tanner scale. RESULTS: There was a significant time-by-group interaction in IGF-I response (p = 0.044; η2 = 0.209) and testosterone (p < 0.001; η2 = 0.508), indicating a greater change in the pubertal group compared to the prepubertal group. Both groups significantly increased post-exercise GH levels (p < 0.05). Only the prepuberal group significantly increased levels of IL-6 at all post-exercise time points (p < 0.05). Both groups showed a significant (p < 0.05) increase in TNF-α levels compared to resting levels. CONCLUSION: These data suggest that acute testosterone and IGF-I response following resistance training differ between trained prepubertal and pubertal male children. Moderate-intensity resistance training performed to failure may thus have different effects in trained prepubertal and pubertal male children, which should be considered when giving training advice. TRIAL REGISTRATION Clinical trials number NCT05022992.