Infrared thermography is a non-invasive, radiation-free tool that enables the evaluation of skin temperature in different regions of the body, providing valuable insights into the physiological state of athletes. This technology allows for the monitoring of thermal changes related to physical exercise, fatigue, and potential injuries, offering crucial information about an athlete’s performance and health.
Below, we present a study by De León-Muñoz et al. (2024) conducted on professional padel players. The main objective of this study was to evaluate the skin thermal asymmetries in professional padel players at three key moments: before (PRE), after (POST), and 10 minutes after training (POST10). Additionally, the study examined the relationship between these asymmetries and perceptual variables such as fatigue and pain, as well as training characteristics, including the players’ experience and racket mass.
The study was conducted with 10 professional players (9 men and 1 woman) from the World Padel Tour and A1 Padel circuits. All participants trained in the same group, following a standardized training pattern that included a combination of game simulations and isolated strokes, with an average session duration of three hours.
Thermal images were taken from 14 regions of interest (ROIs) on each player, covering both upper and lower limbs and the trunk. The players followed the same training protocol, with sessions consisting of game simulations and technical exercises. Skin temperature was measured in the 14 ROIs using a Flir E60bx thermal camera at three key moments: PRE, POST, and POST10. These thermal measurements were analyzed under standardized conditions to ensure result comparability.
Additionally, all participants followed the same pre-test instructions, such as avoiding acclimatization time, therapeutic creams, smoking, intense exercise, or heavy meals, ensuring that prior conditions would not affect the thermographic data.
One of the most interesting findings of the study was that no significant differences were found in the PRE phase, indicating that at rest, and in the absence of pain or injury, players maintain a thermal balance between the dominant and non-dominant extremities. This point is crucial for correctly interpreting thermographic data and establishing a baseline that allows for identifying possible deviations related to physical activity or pathological factors.
After training (POST), significant increases in skin temperature were observed in the dominant extremities compared to the non-dominant ones. The differences were particularly notable in the anterior forearm (30.8°C vs. 29.1°C, p < 0.01), anterior shoulder (31.6°C vs. 30.9°C, p < 0.05), and posterior forearm (30.8°C vs. 29.3°C, p < 0.05), reflecting greater muscle effort and higher metabolic activity in these areas. Additionally, these thermal asymmetries persisted even 10 minutes after training (POST10), suggesting a slower recovery process in the dominant limbs.
It is interesting to note that recent studies by the TERMOINEF research group at the Polytechnic University of Madrid have identified specific thermographic profiles depending on the sport. For example, in sports like football, the tibial anterior region of the dominant leg typically shows a higher temperature than the non-dominant leg. In the case of judo, the characteristic thermal profile is reflected in a higher temperature in the gripping forearm, due to the repeated and continuous use of this technical gesture.
Another particularly interesting example is the study by Marzano-Felisatti, Martinez-Amaya & Priego-Quesada (2023) on tennis players, where basal thermal differences of up to 0.8°C were found in the forearm and posterior thigh of the dominant side. Similarly, judo studies have shown 0.4°C differences in the gripping forearm (Almeida-Júnior et al., 2019), and in football, 0.2°C differences have been reported in the dominant leg (Gomez Carmona, 2012).
The importance of these thermal profiles lies in their ability to help us understand the physiological adaptations of each sport and avoid misinterpretations, as these asymmetries are not always pathological but could be functional adaptations specific to each discipline. However, it is still necessary to further investigate and characterize these profiles across different sports, which opens a wide range of research opportunities for infrared thermography in the sports field.
It is interesting to note that recent studies by the TERMOINEF research group at the Polytechnic University of Madrid have identified specific thermographic profiles depending on the sport. For example, in sports like football, the tibial anterior region of the dominant leg typically shows a higher temperature than the non-dominant leg. In the case of judo, the characteristic thermal profile is reflected in a higher temperature in the gripping forearm, due to the repeated and continuous use of this technical gesture.
Another particularly interesting example is the study by Marzano-Felisatti, Martinez-Amaya & Priego-Quesada (2023) on tennis players, where basal thermal differences of up to 0.8°C were found in the forearm and posterior thigh of the dominant side. Similarly, judo studies have shown 0.4°C differences in the gripping forearm (Almeida-Júnior et al., 2019), and in football, 0.2°C differences have been reported in the dominant leg (Gomez Carmona, 2012).
The importance of these thermal profiles lies in their ability to help us understand the physiological adaptations of each sport and avoid misinterpretations, as these asymmetries are not always pathological but could be functional adaptations specific to each discipline. However, it is still necessary to further investigate and characterize these profiles across different sports, which opens a wide range of research opportunities for infrared thermography in the sports field.
ThermoHuman has had the support of the Funds of the European Union and the Community of Madrid through the Operational Programme on Youth Employment. Likewise, ThermoHuman within the framework of the Export Initiation Program of ICEX NEXT, had the support of ICEX and the co-financing of the European Regional Development Fund (ERDF).
Thermohuman has received funding from the Centre for the Development of Industrial Technology (CDTI), in participation with the European Regional Development Fund (ERDF), for the R+D activities involved in creating a new tool, based on thermography, for the prediction and prevention of rheumatoid arthritis. See project detail.
