A análise da temperatura termográfica da pele é aplicável como parâmetro de monitoramento da carga de treinamento no voleibol?

Abstract

The advancement in the use of infrared thermography in sports, as a method for monitoring training load, has led to an increase in the number of studies using this technique. However, the results are still divergent regarding the behavior of thermographic skin temperature after exercise. Therefore, the overall objective of this thesis was to evaluate the use of thermographic skin temperature as a means of monitoring training load. The thesis was divided into two studies. Study 1 investigated whether measuring thermographic skin temperature (Tskin) using infrared thermography could reflect the accumulation of training load during the preparatory period of a professional volleyball team. Sixteen athletes (20.1 ± 3.1 years, 88.1 ± 6.1 kg, 193 ± 0.1 cm, and 13.3 ± 2.3% body fat) were evaluated over two weeks of the preparatory period (5 training days each week) for the second division of the Brazilian Men's Volleyball Super League. After a week of familiarization with the study procedures, Tskin was measured in eight regions of interest (ROI) (anterior and posterior parts of the arm, shoulder, thigh, and leg) on the first and last training day of each week, along with subjective perception of recovery (SPR), measured on the first and last training day of each week. The training load for each session and the total weekly training load (TWTL) were calculated using the session rating of subjective perception of effort (session RPE) method. Three days in the first week and four days in the second week presented higher training loads (χ2 = 89.1, p < 0.001), as indicated by a significant reduction in SPR at the end of each week (F = 52.3, p < 0.001). Among the eight ROIs examined, five (anterior and posterior shoulder, posterior arm, and anterior and posterior leg) showed a decrease in Tskin after two days of rest (weekend), while two ROIs (anterior and posterior shoulder) showed an increase in Tskin at the end of the following training week (p < 0.05). Of the 44 associations examined between Tskin, SPR, and TWTL, only the associations between the delta PSR and the mean delta of the anterior and posterior leg Tskin were significant (β = − 0.20, p < 0.045 for both). In conclusion, the results of study 1 suggest that Tskin can be altered during the pre-competitive period in professional volleyball players; However, it does not appear to be associated with SPR and training load assessed by the session RPE method. Study 2 aimed to evaluate Tskin 24h after a volleyball training session and relate it to performance variables and SPR. Ten volleyball players from the under-19 category (18.9±1.1 years; 185.4±4.5 cm; 70.3±8.6 kg) participated in the study. Before and 24h after a volleyball training session, the athletes were evaluated in this order: SPR, Tskin of eight ROI (shoulder, pectoral, scapula, abdomen, lumbar, arm, thigh and leg), performance in the countermovement jump and in the push-up with repulsion. There was an increase in maximum Tskin (time to toppass) in the anterior thigh (p<0.05) and leg (p<0.05), and in average and maximum TTP in the posterior shoulder (p<0.05) 24 hours after the training session. No changes occurred in SPR (point of resistance), countermovement jump performance, or push-up with repulsion 24 hours after the training session. A moderate relationship was found between countermovement jump performance and average and maximum Tskin in the posterior thigh and leg (r=0.5; r=0.62; p<0.05) and with average Tskin in the anterior leg (r=0.46, p<0.05). Thus, in conclusion, the results of study 2 indicate that volleyball training affected Tskin in specific areas such as the thigh, leg, and shoulder in players from an under-19 team. However, no relationship was found between changes in Tskin and physical performance.