Ice is applied to injured muscles as a first aid treatment, but what exactly does this have on muscle regeneration? And does it really help? The answer is in a recent Japanese study.
The study was conducted by researchers including Assistant Professor Arakwa Takamitsu of Kobe University's Graduate School of Health Sciences and Assistant Professor Kawashima Masato of Kawasaki Medical University, and published in the American Journal of Physiology-Regulatory, Integrative and Comparative Physiology.
The researchers found that applying ice to lightly injured muscles promoted muscle regeneration. In contrast, the same researchers had previously conducted a previous study on serious muscle injuries and found that applying ice on them may delay recovery.
It is hoped that these findings will be used as a basis for more precise guidance on whether or not to apply ice to such injuries.
What did the researchers find?
- Experiments have shown that applying ice after a mild muscle injury promotes muscle regeneration.
- It is believed that this is the first time in the world that a study has shown a positive effect of icing on muscle regeneration.
- The researchers showed that the extent of the injury may have a greater impact on the effectiveness of the ice than the method or timing.
The role of macrophages
Macrophages are immune cells that regulate the repair of affected muscles. Anti-inflammatory macrophages accumulate at the damaged site shortly after the injury, producing an enzyme called inducible nitric oxide synthase (iNOS), which has a negative side effect that expands the size of the injury.
The researchers' findings revealed that applying ice after a light muscle injury reduces the buildup of these macrophages, thus preventing ice from expanding the size of the muscle injury.
The researchers' next challenge is to determine the extent of muscle injury in proportion to the right amount of ice. Building on their previous investigations, they aim to contribute to guidelines that will enable people in sports and clinical rehabilitation to make accurate judgments about whether or not to put ice on an injury.
After all, if you have an injury, you should see a doctor, but generally using ice for minor muscle injuries may help speed recovery, but this does not apply to severe injuries.