IGF-1, C-Reactive Protein, and Skin Temperature Responses to a Non-Contact Team Sport Activity Circuit in Under-20 Elite Soccer Players

Abstract The aim of the study was to evaluate the responses of insulin-like growth factor 1 (IGF-1), C-reactive protein (CRP), IGF-1/CRP ratio, and skin temperature (Tsk) of the lower limbs (LL) of under-20 elite soccer athletes to a non-contact team sport activity circuit throughout 48h. Thirty elite soccer athletes (19.0 ± 1.0 years, 74.3 ± 7.13 kg, 10.3 ± 2.2 %F, 178.1 ± 6.6 cm, 56.3 ± 3.1 mL.kg-1.min-1) were submitted to a team sport activity circuit with intermittent exercises, jumps, direction shifts, accelerations and decelerations. Plasma concentrations of IGF-1 and CRP were evaluated pre-training session (baseline), and immediately after, and at 3, 24 and 48h following exercise. While the Tsk of the LL was evaluated at baseline, and at 24 and 48h following exercise. Plasma IGF-1 concentrations were greater immediately after, 24 and 48h after the circuit compared to 3h (p< 0.05; ES= 0.66, 0.72 and 0.70, respectively). CRP values did not change throughout the study (p> 0.05). When verifying the IGF-1/CRP ratio, the values at 3h after the activity circuit were lower than those presented in baseline, and immediately after, 24 and 48h after the exercises (p< 0.05; ES= 0.53, 0.65, 0.56 and 0.57, respectively). The hot and neutral zones increased the number of pixels at 24 and 48h after the activity circuit, while the cold zone showed an opposite behavior (p< 0.05). Changes in the values of blood biomarkers and Tsk of the LL suggest that there is possibly an active tissue repair process throughout 48h following exercise.