Relationship Between Skin Temperature Response And Metabolic Flexibility In Endurance Runners And Professional Soccer Players

Abstract

During endurance exercise, skin temperature (Tsk) plays a fundamental role in thermoregulation and might be influenced by aerobic fitness (VO2peak) and metabolic flexibility, both powerful predictors of athletic performance. PURPOSE: The aim was to study the correlation between Tsk response and metabolic flexibility and stress by measuring blood lactate concentrations ([La-]), fat oxidation (FATox) and carbohydrate oxidation (CHOox) rates in highly trained (HT) competitive endurance runners, moderately active (MA) runners and professional soccer (PS) players. METHODS: we used indirect calorimetry, [La-] measurements, and monitored the Tsk response in HT (n = 22; VO2peak = 58.57 ± 2.33 ml/kg/min), MA (n = 20; VO2peak = 49.07 ± 4.67 ml/kg/min), and PS (n = 23; VO2peak = 53.34 ± 3.67 ml/kg/min) during an incremental maximal treadmill test (3-min intervals) until exhaustion, followed by a recovery period of five minutes. Descriptive were obtained for all variables. One-way ANOVA with post-hoc Bonferroni test were performed to compare the groups, and Pearson’s r correlation coefficients to assess the relationships among the variables studied. RESULTS: MA group exhibited lower VO2peak, Speedpeak, and higher BMI and fat mass % (all p < 0.05) than both HT and PS groups. Average FATox rates and Tsk were significantly higher in HT (0.30 ± 0.08 g.min-1; 35.55 ± 0.48 °C) and PS (0.23 ± 0.13 g.min-1; 35.62 ± 0.50 °C) compared with the MA (0.19 ± 0.11 g.min-1; 34.98 ± 0.50 °C) group, respectively (all p < 0.001). Significant correlations were found between [La-] and Tsk for each group (HT: r = 0.572; MA: r = 0.589; PS: r = 0.603), and there were correlations among the average [La-] and the average rates of FATox across the three groups studied (p < 0.05). CONCLUSIONS: These findings indicate that higher VO2peak and FATox rates and lower [La-] were associated with increased Tsk during incremental maximal exercise across individuals of widely different metabolic capabilities. Tsk seems to be a valid biomarker for metabolic fitness, as well as an attractive concept for the assessment and monitoring of athletes during competition. Furthermore, our data show significant differences which should be taken into account when developing individualized strategies for both nutrition and training in order to enhance athletic performance.