Cold, warm or hot? Best practice for muscle injuries treatment

In the fields of sports, health, physiotherapy, and exercise medicine, thermal therapies—such as cryotherapy and hot water immersion—are common strategies used to manage muscle damage. However, their actual effectiveness in promoting muscle recovery and regeneration remains a topic of ongoing debate.
A study published in The Journal of Physiology and led by Dablainville and Racinais has shed new light on the subject: hot water immersion significantly enhances muscle regeneration following a simulated injury, while cold water shows no relevant positive effects. In this article, we’ll summarize the study and highlight key findings.

Study on Muscle Damage

The study involved 34 healthy men who underwent an induced muscle damage protocol using electrically stimulated eccentric contractions of the quadriceps, resulting in muscle fiber necrosis. Participants were then assigned to one of three intervention conditions for 10 days:

• CWI (Cold Water Immersion) – 15 minutes at 12 °C
• TWI (Thermoneutral Water Immersion) – 30 minutes at 32 °C
• HWI (Hot Water Immersion) – 60 minutes at 42 °C

Researchers assessed pain levels, muscle strength, blood markers of damage, muscle temperature, and proteins related to inflammation and regeneration

Key Findings

Strength Recovery

All groups experienced the expected decrease in muscle strength following the induced damage. While the hot water group showed a slight improvement in strength recovery by day 4, the differences were not statistically significant.

To sum up, none of the thermal interventions conclusively improved short-term strength recovery.

Muscle soreness and damage markers

• Hot water immersion significantly reduced perceived pain (measured via VAS scale) compared to the neutral water group.
• Levels of creatine kinase (CK) and myoglobin in the blood were significantly lower in the hot water group compared to both cold and neutral groups, suggesting less muscle damage or faster clearance of these markers.
• Cold water immersion showed no significant benefits in any of these indicators.

Inflammatory and regenerative profile: heat as a modulator

• Hot water immersion increased the expression of HSP27 and HSP70 proteins, which are associated with cell protection and structural regeneration.
• It also led to a higher expression of IL-10, a key anti-inflammatory cytokine, and suppressed the pro-inflammatory NF-κB pathway, indicating an early shift toward a pro-regenerative profile.
• In contrast, CWI did not reduce inflammation or change inflammatory markers compared to the control (thermoneutral) group.

Interpretation and Practical Application

The findings of this study appear to support the use of hot water immersion as a therapeutic strategy to accelerate recovery following muscle injury—particularly in contexts where controlling inflammation, pain, and the molecular environment is critical.
Cryotherapy, despite its widespread use, did not show objective improvements in regenerative processes or clinical symptoms. These results suggest it may be time to reconsider routine use of cold therapy, especially in rehabilitation protocols beyond the acute injury phase.
That said, it’s worth noting that this study simulated a muscle injury; therefore, further research is needed to confirm these results in real-world injury scenarios before generalizing its application. Here an example - tendon injury.

Conclusion

In the context of a simulated muscle injury, daily hot water immersion for 10 days:

• Reduces perceived muscle pain
• Lowers blood levels of muscle damage markers
• Modulates inflammation in a favorable way
• Promotes expression of proteins involved in muscle regeneration

By contrast, cold water immersion did not show any positive effects on these indicators.

These findings reinforce the idea that heat may be a useful tool in the muscle recovery process, while cryotherapy should be applied with more discernment and not assumed to be a universal solution.

Reference:

• Dablainville, V., Mornas, A., Normand‐Gravier, T., Al‐Mulla, M., Papakostas, E., Olory, B., ... & Racinais, S. (2025). Muscle regeneration is improved by hot water immersion but unchanged by cold following a simulated musculoskeletal injury in humans. The Journal of Physiology.