Alongside its benefits, one of the unwelcome outcomes of exercise can be sore muscles and, so, ways to prevent or treat this might be important for athletes, whether they are professional or amateur. In September 2015, as the Rugby World Cup began, a new Cochrane Review examined the evidence on one intervention, whole-body cryotherapy or exposure to extremely cold air. One of the authors, Joseph Costello, from the University of Portsmouth in the UK, tells us more.