The aim of this study was to examine the effects of a prophylactic dose of a local, transcutaneously administered, non-steroidal anti-inflammatory drug on muscle soreness, muscle damage and sprinting performance in young trained males. Twenty-five subjects aged 19+/-3 years, actively participating in rugby union and field hockey, were familiarized with the test procedure and then divided at random into an experimental group (n = 13) and a control group (n = 12). The experimental group received two patches, each containing 40 mg flurbiprofen (TransAct LAT), 12 h before an exercise bout designed to produce delayed-onset soreness (DOMS). The control group received identical non-medicated placebo patches at the same time. Delayed-onset muscle soreness was induced by an exercise protocol consisting of drop jumps (seven sets of 10 repetitions). Serum creatine kinase activity, muscle soreness, muscle girth and acceleration in a maximal sprint over 30 m were measured before the induction of DOMS and at 12, 24, 48 and 72 h thereafter. Plasma lactate concentration was measured 3 min after the 30-m sprint tests. Subjects in both groups had significantly more pain at 24 and 48 h compared with at 12 and 72 h (P < 0.05; Friedman two-way analysis of variance). Thigh girth and serum creatine kinase did not change throughout the experiment. Although plasma lactate concentrations were elevated after the 30-m sprint, there were no differences between groups or as a result of DOMS. The greatest acceleration occurred between 5 and 10 m. This was not affected by the anti-inflammatory drug or DOMS. In conclusion, the aetiology of the DOMS induced in the trained subjects in this study seems to be independent of inflammatory processes or, more specifically, of increases in prostaglandin synthesis in the muscles.