Thermography applied to sports and health allows, through scientific research, to identify the physiological patterns after training.

Depending on the type of training chosen, the scientific literature has shown that certain metabolic pathways become preferential (Chicharro J.L. et al 2006). In addition, certain adaptations are caused by activation in response to the type of stimulus.

As is the case of the opposition between the AMPK binomial and the MTOR1 regulator, both function as opposite regulators depending on the type of stimulus that is performed. Whereas AMPK is a regulator of catabolism that will be requested when we perform resistance exercises. On the other hand, the MTOR1 regulator is related to anabolism and is activated when we perform a force stimulus.

Patterns of thermal response to training

The type of physical training affects body temperature in different ways. Prolonged aerobic exercise lowers the temperature in unstressed areas, increases it in the joints, and remains stable in the exercised regions, producing the "hot-spot pattern."

Strength training causes a hypothermic response, more pronounced in the non-exercised regions, and a transfer of temperature from the muscle groups requested to the surrounding areas of the skin with a more homogeneous pattern in the following hours.

Speed exercise produces a marked drop in body temperature in general immediately after its completion.

But what happens to the temperature after training?

Figure 1. Skin temperature responses to training, immediately after and 8 hours later.

In the hours after training, there is an increase in body temperature because of the activation of the metabolism, which could be related to the EPOC effect. These temperatures reach their greatest increase between 6 and 9 am, depending on the type of stimulus and the muscle groups requested. Therefore, it is important to monitor the skin temperature of the subjects to see their adaptation and recovery from basal temperature after training.

In two recent investigations (of this same 2023), and the thesis of Fernandez-Cuevas 2012, it is observed that regardless of the type of training in the following hours there is a significant increase in body temperature because of the activation of the metabolism that could be related to the COPD effect produced by these. In addition, these temperatures reach their greatest increase between 6 and 9 hours depending on the muscle groups requested and the type of stimulus (Priego-Quesada et al 2022; Fernandez-Cuevas et al. 2023). For all these reasons, it seems interesting to control the skin temperature of the subjects to see how they adapt to this training and how they recover their basal temperature.

From ThermoHuman they advocate recommending that, if the objective is to measure the internal load of training, it is convenient to wait a few hours and not measure immediately after training.

Above all, if we want to control the effect of training, the most interesting thing would be to measure it after 24 hours to control the effects of influencing factors such as sleep or the circadian rhythm.

References

Chicharro, j. l., & vaquero, a. f. (2006). fisiologa del ejercicio/physiology of exercise. ed. médica panamericana.

Priego-Quesada, J. I., Catalá-Vilaplana, I., Bermejo-Ruiz, J. L., Gandia-Soriano, A., Pellicer-Chenoll, M. T., Encarnación-Martínez, A., … & Salvador-Palmer, R. (2022). Effect of 10 km run on lower limb skin temperature and thermal response after a cold-stress test over the following 24 h. Journal of Thermal Biology, 105, 103225.

Fernández-Cuevas, I., Torres, G., Sillero-Quintana, M., & Navandar, A. (2023). Thermographic assessment of skin response to strength training in young participants. Journal of Thermal Analysis and Calorimetry, 1-9.