Effects of Resistance Training on Skin Temperature and Its Relationship with Central Nervous System (CNS) Activation.

Manuel Sillero-Quintana,Ignacio Refoyo,Adérito Seixas,Jacob Jones-Rando,João Carlos Bouzas Marins

doi:10.3390/healthcare10020207

Abstract

The aim of this work was to relate the activation of the sympathetic and parasympathetic nervous systems with the skin temperature (Tsk) of the lower limbs after a resistance training exercise. Under controlled conditions, the average Tsk in the areas of the anterior and posterior thighs, knees and legs was obtained with a thermal imager and the parasympathetic and sympathetic activation was registered with an Omegawave® device on 20 healthy and trained male volunteers (25.39 ± 8.21 years) before exercise, immediately after standard resistance training (3 exercises (2 quadriceps + 1 hamstrings) × 4 sets × 10 repetitions (70% 1RM), 90-sec recovery) and after 20 min of recovery. The results showed a significant effect of exercise and recovery on Tsk in all regions of interest (ROIs) considered (p < 0.05) and strong inverse relationships between sympathetic and parasympathetic activation values. Significant results were found for the total variation of Tsk (p < 0.05) with highly positive values for subjects with lower sympathetic activation and almost null or even negative values for those with higher sympathetic activation. Sympathetic activity was a significant predictor of total Tsk variation in the anterior thigh, posterior thigh and anterior knee but not in the posterior knee, anterior leg, and posterior leg. Baseline Tsk was a significant predictor of total Tsk variation the all ROIs except in the posterior knee. Tsk measured by thermography could be used to estimate the level of participation of muscle areas in exercise and registering the level of sympathetic activation before exercise could be interesting in predicting the athlete’s physiological response to strength training.

Highlights

Infrared thermography (IRT) is making its way into the world of sport, especially in the field of injury prevention [1,2]
Thermographic cameras capture the infrared radiation of the electromagnetic spectrum, converting the radiated energy into information about the superficial skin temperature (Tsk), which is directly related to the local blood flow of the skin
The variation of the sympathetic and parasympathetic activation levels does not show significant differences over time. It is worth noting the high values of the standard deviations both in the case of sympathetic and parasympathetic activation, with values ranging from one third to one half of the mean values of these variables

Summary

Introduction

Infrared thermography (IRT) is making its way into the world of sport, especially in the field of injury prevention [1,2]. There are many medical applications of IRT [3], but some researchers have shown new applications for thermography in the sports area [2], such as quantification of training load [4], detection of biomechanical imbalances [5], injury prevention [1,6] and the effects of the sports practice on the athlete’s skin temperature [7,8,9]. Considering the last application mentioned above, it has been reported that highly trained subjects have a lower Tsk during exercise and need a longer time to recover the baseline Tsk after exercise [5,9]. Athletes may need a longer resting time, being imperative to review their diets, hours of sleep and recovery protocols [2]

Objectives

Methods

Results

Discussion

Conclusion