Jesus Alejandro Escalona Navarro (Chemnitz), Lukas Verderber (Chemnitz), Dr. Daniel Schmidt (Chemnitz), Milena A. dos Santos (Uruguaiana / BR), Dr. Inmaculada Aparicio (Valencia / ES), Prof. Jose I. P. Quesada (Valencia / ES), Prof. Dr. Felipe P. Carpes (Uruguaiana / BR), Dr. Andresa M. C. Germano (Chemnitz)
Abstract-Text (inkl. Referenzen und Bildunterschriften)
Introduction: A substantial proportion of energy generated during muscle contraction dissipates as heat, a pivotal aspect of the body"s thermoregulation [1]. Despite general post-activity skin temperature increases [2,3], its potential use as a fatigue marker remains controversial.
Aim: This study evaluates the sensitivity of skin temperature outcomes to an exercise protocol inducing acute fatigue in the M. triceps surae (TS).
Materials & Methods: 41 participants (24.7 ± 4.3 yrs) underwent pre-, immediately post-, and 10 min post-fatigue thermographic imaging targeting the lower posterior leg area. The Region of Interest (ROI) included the lateral (TSL) and medial (TSM) portions of the TS. The fatigue protocol involved three sets of single-leg calf raises until subjects could no longer sustain the prescribed movement amplitude. Analyzed parameters, including maximal and mean temperature, underwent inferential statistical tests for data analysis.
Results: The skin temperature of the TSM was significantly higher than the TSL at all time points. Maximum skin temperature at the TSM and TSL significantly increased immediately post-fatigue and 10 min later compared to baseline (Table 1). Regarding mean skin temperature, significant increases at the TSM and TSL were exhibited when comparing 10 min post-intervention versus the other two time points. However, no significant immediate mean temperature increase was observed after fatigue.
Summary: Skin temperature responses to fatigue differed between the TSL and TSM. Maximum skin temperature demonstrated greater sensitivity to acute fatigue. Future investigations should explore additional temperature parameters and evaluate the repeatability of the observed responses.
[1] Krustrup et al., J Physiol, 549(1), 255–269 (2003).
[2] da Silva et al., Physiol Meas, 39(10), (2018).
Table 1: Mean ± SD of mean and maximum skin temperature [°C]
A, B, C, D, E, F, G, and H p<0.05 pre vs. post comparisons and * p<0.05 TSL vs. TSM