This study compared the effect of four different intensities of initial eccentric exercise (ECC1) on optimum angle shift and extent of muscle damage induced by subsequent maximal eccentric exercise. Fifty-two male students were placed into 100%, 80%, 60%, or 40% groups (n=13 per group), performing 30 eccentric actions of the elbow flexors of 100%, 80%, 60%, or 40% of maximal isometric strength (MVC) for ECC1, followed 2-3 weeks later by a similar exercise (ECC2) which used 100% MVC load. MVC at six elbow joint angles, range of motion, upper arm circumference, serum creatine kinase activity, myoglobin concentration, and muscle soreness were measured before and for 5 days following ECC1 and ECC2. A rightward shift of optimum angle following ECC1 was significantly (P<0.05) greater for 100% and 80% than 60% and 40% groups, and decreased significantly (P<0.05) from immediately to 5 days post-exercise. By the time ECC2 was performed, only 100% group kept a significant shift (4°). Changes in most of the criterion measures following ECC1 were significantly greater for 100% and 80% groups compared with 60% and 40% groups. Changes in the criterion measures following ECC2 were significantly (P<0.05) greater for 40% group compared with other groups. Although the magnitude of repeated bout effect following ECC2 was significantly (P<0.05) smaller for 40% and 60% groups, all groups showed significantly (P<0.05) reduced changes in criterion measures following ECC2 in comparison to the ECC1 100% bout. We conclude that the repeated bout effect was not dependent on the shift of optimum angle.