New study shows icing muscles after exercise ineffective, counter-productive 26 Apr, 2021 10:31 PM 5 minutes to read New York Times After a particularly vigorous workout or sports injury, many of us rely on ice packs to reduce soreness and swelling in our twanging muscles. But a cautionary new animal study finds that icing alters the molecular environment inside injured muscles in detrimental ways, slowing healing. The study involved mice, not people, but adds to mounting evidence that icing muscles after strenuous exercise is not just ineffective; it could be counter-productive. Check inside the freezers or coolers at most gyms, locker rooms or athletes' kitchens and you will find ice packs. Nearly as common as water bottles, they are routinely strapped onto aching limbs after gruelling exercise or possible injuries. The rationale for the chilling is obvious. Ice numbs the affected area, dulling pain, and keeps swelling and inflammation at bay, which many athletes believe helps their aching muscles heal more rapidly.