Thermography offers us objective information on how warm-up affects the body. We analyze a study measuring knee temperature before and after exercise.

Warm-up is an essential step before any training session or competition. However, not all types of warm-up produce the same effects on the body. Is a static or dynamic warm-up more effective? A recent study published in Frontiers in Physiology provides a new perspective thanks to infrared thermography: observing in real time how the knee responds to each type of preparation.

The Study

A total of 85 young participants (46 men and 39 women) took part in the research. They were divided into two groups: one performed a static warm-up (sustained stretches after light jogging) and the other a dynamic warm-up (repeated movements of flexion, extension, adduction, and abduction).

Afterward, all participants completed a 90° change of direction (COD) exercise, a movement that places high load on the knee joint and is associated with increased injury risk, such as anterior cruciate ligament (ACL) tears.

Using a thermographic camera (FLIR E54 model), knee temperature was recorded at four time points:

• Initial rest (T0)
• After warm-up (T1)
• After the COD exercise (T2)
• Recovery after 20 minutes of rest (T3)

Four regions of interest were analyzed: upper anterior, lower anterior, upper posterior, and lower posterior.

Main Results

The findings were:

• Sex differences: men showed higher temperatures than women at all stages.
• General trend: knee temperature dropped slightly after warm-up, decreased further after the COD exercise, and returned to similar or higher values after recovery.
• Effect of warm-up type:
  • Static warm-up produced significant temperature decreases in the lower anterior region in both men and women, and in the upper posterior region in men.
  • Dynamic warm-up did not show relevant changes in any of the analyzed regions.

What Does This Thermal Pattern Mean?

A decrease in skin temperature can be interpreted as a redirection of blood flow: blood shifts from the skin to the muscles about to be used. In other words, it indicates that deep tissues are more prepared to handle the load.

In this sense, static warm-up seems to better facilitate this thermal response in the knee before a demanding exercise such as a 90° COD, which could help prevent injuries and optimize performance.

Practical Implications

The results provide useful insights for coaches, trainers, and health professionals:

• Static warm-up, often questioned in recent years, may play a positive role in specific knee preparation, at least for high-demand exercises such as changes of direction (COD).
• Personalization by sex could be relevant, as men and women showed different thermal responses.
• Infrared thermography proves to be an objective, non-invasive tool to monitor how the body responds to warm-up, providing data that goes beyond subjective perception.

Conclusion

The study shows that not all warm-ups are equal: the choice between static and dynamic may influence the physiological preparation of the knee. Thanks to thermography, we now know that static warm-up triggers more pronounced thermal adaptations, especially in men, which could translate into better joint readiness for high-demand efforts.

In a context where injury prevention and performance optimization are priorities, combining scientific evidence with objective tools such as thermography opens new opportunities for individualized training.

Reference

Trovato, B., Sortino, M., Petrigna, L., Roggio, F., & Musumeci, G. (2024). The influence of static and dynamic warm-up on knee temperature: infrared thermography insights before and after a change of direction exercise. Frontiers in Physiology, 15, 1393804.