Ice therapy can be an effective first aid solution, yet its exact effect on muscle regeneration remains uncertain. A study suggests that when used, its application depends on the severity of injury.

RICE (Rest, Ice, Compression and Elevation) is a widely utilized treatment method for acute sports injuries.

As soon as an injury has been sustained, various steps can be taken to treat it in the future. While evidence on icing’s benefits is scarce and opinions differ on its applicability or otherwise.

Researchers conducted several experiments to investigate the effectiveness of icing. Although no prior animal studies suggested otherwise, no indication has ever been provided by icing that muscle regeneration is enhanced through this practice.

For this study, they focused on altering the severity of muscle injuries during tests. This approach is taken as most sporting-related muscle injuries tend to be limited; for instance, less than 10% of myofibers (muscle fibers) become necrotized and damaged over time.

All animal studies conducted thus far have examined more severe injuries, in which more than 20% of myofibers had been damaged.

So, the researchers created a mildly injured muscle animal model and evaluated its use with similar applications of ice after injury using similar methods as used before.

Previous studies conducted by them resulted in injuries affecting 20% of total muscle fibers; for the current one they induced an injury affecting 4%, which reflects injuries often seen after physical activities like long distance running or vigorous exercises.

Icing was performed using polyethylene ice bags applied directly onto the skin surface in three 30-minute sessions 90 minutes apart over three days following injury (i.e. 3 sessions immediately following injury, 3 one day post injury and three two day post injury), using an identical method as used in the prior study.

Studies of two weeks after injury found significant variations between icing groups and non-icing groups for muscle cross-sections that had undergone regeneration, suggesting that icing could help facilitate muscle regeneration.

Macrophages are immune cells responsible for managing muscle injuries. Following injury, pro-inflammatory macrophages quickly accumulate around damaged areas; however, some express nitric oxide synthase, which has the side-effect of increasing injury sizes.