ESPE Abstracts

Introduction: The relationship between sports intensity and growth has become a concern in teenagers. Changes in the GH/IGF1 axis have been studied as biomarkers for training intensity in adolescents; however, reports on the effects of physical effort on GH and IGF1 levels are discordant and studies on GH and IGF1 responses in combat sports are scarce.

Aim: To investigate the effects of a Jiu-Jitsu training session on serum IGF1 and IGFBP3 concentrations.

Methods: Nine male Jiu-Jitsu fighters (25±4.7 years), representing a sample of the National Elite in the sport in Brazil with 5.4±2.7 years of practice, were studied. Blood samples for serum IGF1 and IGFBP3 determinations (ELISA) were collected at the beginning (after 30 min rest) and immediately after the training session, which consisted of six 7.5-min fights. The fighters’ perception of the intensity of the effort was recorded. Data was analyzed by Wilcoxon test at 5% significance (P<0.05).

Results: The intensity of the effort was rated ‘hard’ and ‘very hard’ by the athletes. No significant difference was observed on IGF1 (P=0.57) or IGFBP3 (P=0.73) levels before or after the training session. Seven athletes had IGF1 levels below the 25th centile (<P10 in two of them) and six showed IGFBP3 levels lower than 4 mg/l.

Discussion and conclusion: Differently to previous studies, which reported reductions in IGF1 in wrestling fighters after training, a hard training session by National Elite Brazilian Jiu-Jitsu fighters did not have a significant effect on IGF1 or IGFBP3 concentrations. This was probably due to the training status of the fighters, who were at their maximum level of performance in the season and/or to their already low levels of IGF1 and IGFBP3 before training session. Furthermore, our findings support the use of acute changes in GH/IGF1 as biomarkers for training intensity/status in combat sports.