New research suggests that ice baths aren't helpful for repairing and building muscle over time, because they decrease the generation of protein in muscles.

The idea behind ice baths is that by reducing body temperature, this in turn reduces blood flow, swelling and inflammation in tissues of the muscles. It’s the same concept as the one behind icing a sprained ankle.

While research has in fact confirmed that ice baths can be helpful for reducing muscle soreness, its effects on the formation of new proteins in the body, important for repairing and building muscle, are more controversial.