Content updated as of 08/04/2026

In the realm of athletic performance, maintaining a constant core temperature is a crucial physiological mechanism. However, skin temperature (Tsk) is highly variable and serves as a direct indicator of individual thermoregulatory capacity. During exercise, excess metabolic heat generated by skeletal muscle contraction is transferred to the surface to be dissipated—a process mediated by vasodilation and peripheral blood flow.

While environmental and circadian factors influence this thermal response, an athlete's anthropometric characteristics play a decisive mechanical role. A study published in the Journal of Thermal Biology by Korman et al. (2024) investigated how specific body components, evaluated using Dual-energy X-ray Absorptiometry (DXA) technology, interact with skin temperature response measured via infrared thermography during progressive exercise to exhaustion and subsequent recovery.

Methodology: DXA and Thermographic Monitoring

To isolate the effect of training modality and aerobic capacity, the study analyzed 42 male athletes divided into four distinct physiological profiles (power-speed vs. endurance):

• Futsal players
• Endurance athletes
• Sprinters
• Recreational runners

Evaluation Protocol

• Gold Standard Body Composition: Dual-energy X-ray Absorptiometry (DXA) was used to quantify active skeletal muscle mass, total fat tissue, and lower-limb-specific fat tissue with high precision. This method overcomes the limitations of earlier tools such as bioelectrical impedance analysis (BIA) or skinfold thickness measurements.
• Longitudinal Thermal Evaluation: Tsk was recorded using infrared thermography across three phases:
  • At baseline rest.
  • During an incremental treadmill test to exhaustion.
  • During a 30-minute recovery period.

Key Findings

1. Skin Temperature Dynamics During Running

Regardless of the athletic group, a clear physiological pattern was observed:

• Exercise Phase: Lower-limb Tsk began to drop right from the onset of exertion, showing a statistically significant decline (p < 0.001) upon reaching speeds of 12 km/h. This is associated with a peripheral vasoconstriction response that redistributes blood flow toward active musculature.
• Recovery Phase: Immediately post-exercise, rapid skin rewarming occurred—particularly pronounced during the first 5 minutes—driven by reactive vasodilation to dissipate accumulated heat.
• The Role of Adipose Tissue: A significant negative correlation was found between Tsk and both total body fat percentage (r between -0.51 y -0.63) and lower-limb fat percentage ($r between -0.50 y -0.71). Higher body fat levels resulted in lower recorded skin temperatures across all stages of the test.

2. The Myth of Body Mass Index (BMI) and Muscle Mass

• BMI is Unreliable: The study demonstrated that the correlation between Tsk and BMI was inconsistent (present only at exercise onset and during recovery). In elite athletes, BMI fails to distinguish between muscular hypertrophy and adipose tissue; thus, it should not be used to predict thermal variations.
• No Correlation with Muscle Mass: Contrary to the hypothesis that larger muscles (greater heat generators) would induce higher surface Tsk, no correlation was observed between Tsk and skeletal muscle mass or the relative skeletal muscle index.

Practical Applications: Interpreting Thermography in High Performance

The findings of this study demonstrate that the skin-subcutaneous tissue complex does not merely act as a passive insulator, but plays an intricate role in thermal energy exchange. This carries direct implications for day-to-day operations of technical and medical staff:

• Contextualizing the Thermal Baseline: When assessing a team's baseline thermal profile, strength and conditioning coaches must know their athletes' actual body composition (via DXA). Players with higher subcutaneous fat percentages will naturally exhibit lower baseline Tsk profiles due to the insulating effect. This indicates distinct morphology rather than pathology.
• Managing Heat Dissipation (Thermal Fatigue): Because fat acts as a barrier to heat flow from muscle to skin, athletes with greater peripheral adipose tissue may face greater difficulty dissipating deep metabolic heat during maximal exercise. Active cooling strategies should be planned for these specific profiles.
• Discarding BMI as an Adjustment Variable: Thermal analysis software and databases must discard BMI as a correction factor for elite athletes. Risk stratification should rely on direct body composition metrics, such as segmented fat tissue.

Conclusion

Running at increasing intensities to exhaustion induces a progressive decline in lower-limb skin temperature, followed by post-exercise rewarming. Thermography reveals that this dynamic is strongly modulated by fat mass percentage, which shows a significant inverse correlation with Tsk. Therefore, integrating precise body composition data is a methodological requirement for accurately interpreting thermoregulatory adaptations and load management in professional athletes.

Reference

• Korman, P., Kusy, K., Straburzyńska-Lupa, A., Sillero-Quintana, M., Zarębska, E., & Zieliński, J. (2024). Exploring the correlation of skin temperature and body composition in athletes undergoing exhaustive physical exercise. Journal of Thermal Biology, 123, 103918.