Food components and the timing of supplements have been shown to affect many aspects of skeletal muscle metabolism, such as glycogen depletion and protein synthesis (Kuo et al, 1999; Rasmussen et al, 2000; Tipton et al, 2001). The aim of the study was to examine whether ingestion of protein following eccentric exercise (EE) could affect recovery and alleviate symptoms associated with delayed onset of muscle soreness (DOMS) in the 72h post exercise period. Methods: Eight male subjects (Age 21 ± 1 yrs; Mass 76 ± 3 kg; Height 180 ± 1 cm Mean ± SEM) volunteered to take part in the study. Each subject visited the lab on two separate occasions separated by 14 days. A 10ml venous blood sample was taken following an overnight fast and analysed for serum Creatine Kinase (CK) and Protein Carbonyl (PC) content by ELISA. Peak isometric maximum voluntary contraction (MVC) and peak power output (PPO) were determined using a custom built isometric rig and SRM fitted cycle ergometer, respectively. Subjects completed a 30-minute downhill run (-10°) at a target heart rate of 150 ± 5 bpm (Braun and Dutto, 2003). On completion, the subjects ingested either a protein meal containing 40g EAA (PRO) or placebo (PLA) solution in a randomised, blind procedure. Venous blood was taken; MVC and PPO were recorded in the subsequent 24, 48 and 72h. DOMS was assessed by algometry. Each subject repeated the experiment a minimum of two weeks later taking the different meal to their first visit. Differences between treatments was analysed for statistical significance using stats. Ethical approval was granted by the University of Brighton Ethical Committee. Results: MVC significantly declined (p<0.05) at 24h post EE in PLA group (-7%) and remained depressed at 48h in the placebo condition (-10%), whereas MVC stayed within pre EE values in the PRO trial at all time points. PPO also declined, reaching a significant (p<0.05) nadir at 24h in the PRO group (-7.9%) and at 48 h in the PLA group (-6%) when PPO had returned to pre EE values in the PRO group. CK, PC and muscle soreness significantly increased (p<0.05) post EE in both groups, which peaked at 24h and endured to 72h, with PRO demonstrating no difference from PLA. Conclusion: Eccentric exercise resulted in a decline in MVC and PPO and an associated increase in CK, PC and DOMS in the 72 h post exercise. Protein ingestion attenuated the performance depressive effect of DOMS on MVC, with no significant effect on PPO recovery. PRO did not affect the increase in muscle damage markers following EE. Protein supplementation may therefore improve MVC recovery following muscle damaging exercise.