Correlation between skin temperature in the lower limbs and biochemical marker, performance data, and clinical recovery scales.

Objective: The purpose of this study was to assess the correlation between thermography and commonly used tools, such as common clinical complaints in athletes, a biochemical marker for muscle damage, and performance data during an official match. Methods: Twenty-two athletes from a professional soccer club (age 27.7 ± 3.93 years; BMI 24.35 ± 1.80 kg/cm²) were followed during the season of a national championship. At each match, the athletes used a Global Positioning System (GPS) device to collect performance data. Forty-eight hours after each match, every athlete's perception of recovery, fatigue, and pain was documented. Blood was collected for creatine kinase (CK) analysis, and infrared thermography was applied. Only athletes who presented pain above five in either limb were included for thermographic analysis. Each thermographic image was divided into 14 regions of interest. For statistical analysis, we included only the images that showed differences ≥ 1° C. Data normality was verified by the Kolmogorov-Smirnov test with Dallal-Wilkinson-Lilliefors correction. We used the Pearson correlation coefficient to verify the correlation between infrared thermography and the following variables.  Results: No correlation was observed between mean skin temperature and blood CK levels, pain level, perception of recovery, and perception of fatigue (r <0.2). Conclusion: Infrared thermography did not correlate with CK level, pain, fatigue perception, or recovery, nor with performance variables within the field.