EFFECT OF A NEGATIVE GRADE AND EXERCISE INTENSITY ON FEMALES' MAXIMAL ECCENTRIC STRENGTH AND DOMS 999

Abstract

The purpose of this study was to determine the effect of a -10% grade and exercise intensity on eleven females' (mean age, 20 yrs) maximal eccentric strength (MES), and delayed onset of muscle soreness (DOMS). Subjects were randomly divided into two treatment groups: low intensity (LI) and high intensity (HI). Exercise intensities were 50 and 70% of VO2max (mean, 42.1 ml·kg-1·min-1) for a treatment distance of 1 mile. The MES was measured by a Biodex at 60 and 90 deg·sec-1 for flexion and extension (immediate, 24, 48, 72 hrs post-exercise). Questionnaires were used to determine DOMS (24, 48, 72 hrs). The data were analyzed by a two-way ANOVA for repeated measures followed by a Fischer's test. Determination of significance was at the p<0.05 level. The results indicate no significant difference for MES at 60 and 90 deg·sec-1 for flexion and extension. A significant increase in DOMS existed at all data collection points for the HI treatment. These data suggest that exercise at a -10% grade at different exercise intensities for a 1 mile duration has no effect on MES, however exercise at a higher intensity elicited a higher DOMS rating. An association between DOMS, muscle damage, and decreases in maximal concentric strength (MCS) is well documented following a down-hill exercise bout. This study represents the first data on the effect of down-hill running on MES. The contradictory findings when compared to MCS studies may be explained by the fact that eccentric muscle contractions utilize different motor recruitment patterns or that the muscle damage occurred predominantly to Type l oxidative muscle fibers which has no effect on MES.