RESIDUAL MUSCULAR SWELLING AFTER REPETITIVE ECCENTRIC CONTRACTIONS

Eight healthy male subjects were asked to exercise their right lower leg anterior compartment eccentrically and their left concentrically. Overall morphology of the specimens revealed a greater cross-sectional fiber area in the eccentrically exercised muscle as compared with the concentrically exercised muscle. Scant evidence of inflammation and no fiber necrosis was observed. Fiber type proportions were equal on both sides and type 1 fiber biased (70%). Extremely large type 2 fibers were found in 4 of 8 subjects from the eccentric specimens. It is concluded that muscle fiber swelling is a predominant feature following eccentric exercise and is directly associated with delayed muscle soreness.