Purpose: This study was conducted to determine if 6 wk of supplementation with vitamins E and C could alleviate exercise-induced muscle damage. We studied 22 runners during a 50-km ultramarathon.
Methods: Subjects were randomly assigned to one of two groups: (a) placebos (PL) or (b) antioxidants (AO) (1000 mg vitamin C and 300 mg RRR-α-tocopheryl acetate). Blood samples were obtained before supplementation (baseline), 24 h pre-, 12 h pre-, and 1 h prerace; midrace, postrace, 2 h postrace, and for 6 d postrace. Plasma α-tocopherol (α-TOH), ascorbic acid (AA), and muscle damage markers (creatine kinase (CK) and lactate dehydrogenase (LDH)), as well as maximal voluntary contraction (MVC) of the hamstring and quadriceps were assessed.
Results: With supplementation, plasma α-TOH and AA increased in the AO but not the PL group. LDH and CK increased in response to the race; LDH peaked at postrace and CK reached maximal values 2 h and 1 d postrace; neither was affected by treatment. Adjusting for between-subject differences in baseline CK values revealed that men had higher levels of CK than did women throughout the study. Correcting CK values for lean body mass (kg) eliminated sex differences, but not changes over time. CK was significantly correlated (R = 0.52, P < 0.0001) with C-reactive protein, an acute phase response marker. MVC decreased 14–26% in all groups in response to the run. Eccentric hamstring (EH) torque and concentric quadriceps (CQ) power exhibited the largest deficits, 26 and 24%, respectively, with no effect of treatment. CQ recovered at a faster rate in women than in men.
Conclusion: Antioxidants appeared to have no effect on exercise-induced increases in muscle damage or recovery, but important sex differences were observed.
1Department of Nutrition and Exercise Sciences, Oregon State University, Corvallis, OR; 2Linus Pauling Institute, Corvallis, OR; and 3Department of Nutrition and Food Management, Oregon State University, Corvallis, OR
Address for correspondence: Maret G. Traber, Linus Pauling Institute, 571 Weniger Hall, Oregon State University, Corvallis, OR 97331; E-mail: firstname.lastname@example.org.
Submitted for publication October 2004.
Accepted for publication April 2005.
Special thanks to Lee Moore for extensive help with Kincom data compilation and analysis; Dr. Gianni F. Maddalozzo for his contribution to the muscle testing protocol; Dr. Robert P. O'Donnell for statistical consulting; Dr. Jeff Zachwieja, Gatorade, for providing the Gatorade sports drinks for participants; Tim Corliss, Clif Bar Inc., for providing Clif Shots for subjects; Clem LaCava, the McDonald Forest Ultramarathon Race Promoter; Dr. James Clark, Cognis Health and Nutrition, for providing vitamin E capsules and matched placebos and the labeled vitamin E (RRR-α-5,7-(CD3)2-tocopheryl acetate); and Dr. Klaus Krämer, BASF, for providing vitamin C tablets and matched placebos. The results of the present study do not constitute endorsement of any products by the authors or ACSM.
This publication was made possible by grant number ES11536 from the National Institute of Environmental Health Sciences (NIEHS), NIH.
This work was presented in part at the Annual Meeting of the American College of Sports Medicine in San Francisco, CA on May 29, 2003 and was published in abstract form in 2003 (Med. Sci. Sports Exerc. 35(5): S197).