ECCENTRIC EXERCISE EFFECTS ON BLOOD GLUTATHIONE STATUS, CK AND DOMS

Abstract

190 This study examined the effects of eccentric exercise on blood glutathione status to determine if there was a relationship between delayed onset muscle soreness (DOMS), creatine kinase (CK) and oxidative stress. Eight healthy male subjects (26.5 ± 1.5yrs) performed a single bout of 60 eccentric elbow extensions using their nondominant arm. Blood and muscle soreness parameters were obtained prior to, immediately after, 24, 48, 72 and 96 hrs after the eccentric exercise. Performance measures were compared in both dominant and nondominant arms. No changes in the dominant arm were noted. Maximum isometric force significantly decreased immediately to 96 hrs, range of motion decreased 24-96 hrs, and DOMS increased 24-72 hrs (p<0.02) in the nondominant arm as indicated by repeated measures ANOVA. DOMS peaked at 48 hrs (5.84 ± .93) compared to baseline (1.4 ± .2) and CK peaked at 72 Hrs (1620 ± 500 IU) compared to baseline (140 ± 47). Glutathione in the reduced form (GSH) was not significantly affected but did decrease 23% at 24 hr and continued at this level for 96 hrs. Oxidized glutathione (GSSG) was .16 mM and was fairly stable over time. Total glutathione was .87 mM and fluctuated very little over the times measured (.73-.87 mM). There were no significant correlations between either blood GSH or GSSG and DOMS and CK. The results suggest that eccentric exercise can result in DOMS and CK release into the blood without alterations in glutathione status. These results indicate that DOMS and muscle damage are not related to oxidative stress in the blood as monitored by glutathione status. This does not rule out oxidative stress as a contributory factor to muscle membrane damage.