Does Combined Antioxidant Vitamin Supplementation Blunt Repeated Bout Effect?
F. He1, J. A. K. Hockemeyer2, D. Sedlock2
Key words ▶ vitamin C and E ● ▶ CK ● ▶ ORAC ●
Health and Exercise Sciences, Skidmore College, Saratoga Springs, United States Health and Kinesiology, Purdue University, West Lafayette, United States
We investigated the effect of antioxidant supplementation on markers of muscle damage, antioxidant status, and delayed onset of muscle soreness (DOMS) after repeated downhill runs. Moderately-trained males (n = 22) were randomly assigned to a supplement (S) or placebo (P) group. Capsules (vitamin C:1 000 mg/d; vitamin E: 400 IU/d) were ingested daily for 2 weeks. before the first (1D) and second (2D) downhill runs, and for 2 additional days following each run. Creatine kinase (CK) activity and oxygen radical absorbance capacity (ORAC) were measured pre-exercise and at 0 (immediately), 6, 24
accepted after revision October 08, 2014 Bibliography DOI http://dx.doi.org/ 10.1055/s-0034-1395630 Published online: January 21, 2015 Int J Sports Med 2015; 36: 407–413 © Georg Thieme Verlag KG Stuttgart · New York ISSN 0172-4622 Correspondence Dr. Feng He Health and Exercise Sciences Skidmore College 815 North Broadway Saratoga Springs United States 12866 Tel.: + 1/518/680 8353 Fax: + 1/518/580 8356 [email protected]
Unaccustomed eccentric exercise elicits muscle damage, produces delayed onset muscle soreness (DOMS) and results in impaired antioxidant capacity. Impaired antioxidant capacity results from an elevation in reactive oxygen species (ROS), initially from a primary source (i. e., superoxide leakage from mitochondrial electron transfer due to increased oxygen consumption during intense exercise) and subsequently from a secondary source (i. e., an oxidative burst by infiltrated neutrophils and macrophage phagocytosis during the muscle repair process) [14, 31, 49, 53]. Other potential ROS sources include the production of xanthine oxidase, nicotinamide adenine dinucleotide phosphate oxidase, and disruption of calcium ion homeostasis [6, 22, 25]. The decrease in antioxidant capacity due to excessive ROS production leads to DNA damage and protein and lipid peroxidation, contributing to muscle damage. Acute eccentric exercise also provides a protective effect whereby these undesirable physiological responses are attenuated following a
and 48 h post-exercise (POST). DOMS was rated for quadriceps, hamstring, gluteus, gastrocnemius, and tibialis anterior at 0, 24, 48 and 72 h POST. CK at 48 h following 1D remained elevated above pre-exercise only in P (P