C-Reactive Protein and Skin Temperature of the lower limbs of Brazilian elite soccer players like load markers following three consecutive games.

The aim of the study was to compare the levels and relative responses of C-Reactive Protein (CRP) and Skin Temperature (Tsk) of the lower limbs (LLs) of elite soccer players following three consecutive games with short intervals (< 4 days). Eleven male professional athletes (age, 29.26 ± 4.52 years) from an Brazil elite team were evaluated, with measurements obtained before (Baseline), and at Post-Games times (24, 48 and 72h). CRP and Tsk levels at 24 h and 48 h Post-Games times were higher than Baseline levels (CRP, p < 0.001, d > 0.9; Tsk, p < 0.04, d > 0.58), additionally, the levels of these variables (CRP vs. Tsk) showed positive correlations (p < 0.05, rs = 0.60-0.88). The relative responses these variables were evaluated (Δ%CRP; Δ%Tsk). The 48h responses of Game 3 are respectively higher than 48 h responses of games 1 and 2, in Δ%CRP (p < 0.03; G3 vs. G1, r = 0.66; G3 vs. G2, r = 0.88) and in Δ%Tsk (p < 0.003; G3 vs. G1, r = 0.88; G3 vs. G2, r = 0.88). The 48 h Post-Game time seems to represent valuable contributions to understanding the development regarding the magnitude and duration of inflammatory processes associated with recovery. Additionally, the positive correlations that were verified allow an increase in the robustness of the analysis of the load of consecutive games through CRP and Tsk of the LLs. Then, these results indicate a physiological stress and a probable cumulative effect of the game loads due to short intervals (< 4 days), which is reinforced by the verified outcome of the Total Distance covered (G3 < G2, p = 0.003; r = 0.88). These findings can contribute to better load control and greater robustness of injury prevention programs.

Correlation between strength and skin temperature asymmetries in the lower limbs of Brazilian elite soccer players before and after a competitive season.

This study aimed to investigate the correlation between strength and skin temperature (Tsk) asymmetries in the lower limbs of elite soccer players before and after a competitive season. The sample (n = 20) was composed of elite male soccer players. Strength asymmetry and Tsk asymmetry was measured through the countermovement jump (CMJ) test and infrared thermography, respectively. Asymmetries were quantified using the symmetry angle (SA) equation. A strong correlation was found between the SA of rate of force development (RFD) and the SA of Tsk before (baseline) (r = 0.7; r2 = 0.43; p = 0.03) and after (r = 0.6; r2 = 0.42; p = 0.04) the competitive season. Moreover, after the competitive season there were significant decreases in Peak force (p < 0.018), Impulse (p < 0.04), RFD (p = 0.0001) and CMJ height (p = 0.05), and significant increases in Tsk (p < 0.03), C-reactive protein (p = 0.03), Creatine kinase (p = 0.0001) and Cortisol (p = 0.04), even after a 3-day rest interval (no training). These results suggest that the CMJ test can be combined with infrared thermography for monitoring strength asymmetry and contribute to the prevention of muscle injuries.