The IGF-I/cortisol ratio as a useful marker for monitoring training in young boxers

• Main Authors: S Nassib (Author), W Moalla (Author), S Hammoudi-Nassib (Author), M Chtara (Author), Y Hachana (Author), Z Tabka (Author), K Chamari (Author), M Elloumi (Author)
• Format: Book
• Published: Termedia Publishing House, 2016-01-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.
• Notes: 0860-021X; 2083-1862; 10.5604/20831862.1180172
• Keywords: Training intensity; Hormonal responses; Physiological demands; biochemical factor; Physical performance; Sports medicine; RC1200-1245; Biology (General); QH301-705.5
• Source: Biology of Sport, Vol 33, Iss 1, Pp 15-22 (2016)

Training effects on plasma insulin-like growth factor-1 (IGF-1)/cortisol ratio were investigated in boxers. Thirty subjects were assigned to either the training or the control group (n=15 in both). They were tested before the beginning of training (TO), after 5 weeks of intensive training (T1), and after 1 week of tapering (T2). Physical performances (Yo-Yo intermittent recovery test level-1), training loads, and blood sampling were obtained at T0, T1, and T2. Controls were only tested for biochemical and anthropometric parameters at T0 and T2. A significantly higher physical performance was observed at T2 compared to T1. At T1, cortisol levels were significantly increased whereas IGF-1 and insulin-like growth factor binding protein-3 (IGFBP-3) levels remained unchanged compared to baseline. At T2, cortisol levels decreased while IGF-1 and IGFBP-3 levels increased. The IGF-1/cortisol ratio decreased significantly at T1 and increased at T2, and its variations were significantly correlated with changes in training loads and Yo-Yo intermittent recovery test level 1 (IRT1) performance over the training period. Cortisol variations correlated with changes in training load (r=0.64; p<0.01) and Yo-Yo IRT1 performance (r=O.78; p<0.001) at T1 whereas IGF-1 variations correlated only with changes in Yo-Yo IRT1 performance at T2 (r=0.71; p<0.001l. It is concluded that IGF-1/cortisol ratio could be a useful tool for monitoring training loads in young trained boxers.