Study: Icing Sore Muscles After Exercise Is a No-GoLong day on the trail, in the water, at the gym? Lots of us reach for ice packs after taxing the bejesus out of our bodies, numbing sore muscles, trying to keep down inflammation. Researchers at Kobe University in Japan conducted a study using mice to compare recovery rates between mice with tiny ice packs applied to their sore bodies and those without. Every aspect of the healing process was delayed in mice that had ice packs applied after their workout. Two weeks later, while the non-ice using mice were raring to go, the iced mice still showed evidence of tissue damage.