The effects of warm underwater water-jet massage on neuromuscular functioning, selected biochemical parameters (serum creatine kinase, lactic dehydrogenase, serum carbonic anhydrase, myoglobin, urine urea and creatinine) and muscle soreness were studied among 14 junior track and field athletes. Each subject spent, in a randomized order, two identical training weeks engaged in five strength/power training sessions lasting 3 days. The training weeks differed from each other only in respect of underwater water-jet massage treatments. These were used three times (20 min each) during the treatment week and not used during the control week. During the treatment week continuous jumping power decreased and ground contact time increased significantly less (P < 0.05) and serum myoglobin increased more than during the control week. It is suggested that underwater water-jet massage in connection with intense strength/power training increases the release of proteins from muscle tissue into the blood and enhances the maintenance of neuro-muscular performance capacity.