Twenty-three trained men took either a single (3 g) dose of HMB free acid or a placebo 60 minutes before undergoing a single bout of high-intensity exercise. The exercise bout resulted in muscle swelling, decreased jump performance, and decreased force production in both groups, but the participants’ highly trained status allowed for a quick return to normal (within 24 h). However, the single dose of HMB free acid significantly improved recovery of work capacity; the men who took HMB recovered work capacity in just 24 hours, while the placebo group had not yet recovered at 72 hours. Thus, even a single dose of HMB free acid allowed the participants to recover to their full training capacity much sooner after a strenuous, high intensity training session.