Contraction-induced muscle damage is unaffected by vitamin E supplementation.
OBJECTIVE
Vitamin E supplementation may confer a protective effect against eccentrically biased exercise-induced muscle damage through stabilization of the cell membrane and possibly via inhibition of free radical formation. Evidence supporting a protective role of vitamin E after contraction-induced muscle injury in humans is, however, inconsistent. The present study sought to determine the effect of vitamin E supplementation on indices of exercise-induced muscle damage and the postexercise inflammatory response after performance of repeated eccentric muscle contractions.


METHODS
Young healthy men performed a bout of 240 maximal isokinetic eccentric muscle contractions (0.52 rad.s-1) after being supplemented for 30 d with either vitamin E (N = 9; 1200 IU.d-1) or placebo (N = 7; safflower oil).


RESULTS
Measurements of torque (isometric and concentric) decreased (P < 0.05) below preexercise values immediately post- and at 48 h post-exercise. Biopsies taken 24 h postexercise showed a significant increase in the amount of extensive Z-band disruption (P < 0.01); however, neither the torque deficit nor the extent of Z-band disruption were affected by vitamin E. Exercise resulted in increased macrophage cell infiltration (P = 0.05) into muscle, which was also unaffected by vitamin E. Serum CK also increased as a result of the exercise (P < 0.05) with no effect of vitamin E.


CONCLUSIONS
We conclude that vitamin E supplementation (30 d at 1200 IU.d-1), which resulted in a 2.8-fold higher serum vitamin E concentration (P < 0.01), had no affect on indices of contraction-induced muscle damage nor inflammation (macrophage infiltration) as a result of eccentrically biased muscle contractions.
Beaton
Louise J
LJ
Department of Kinesiology, McMaster University, Hamilton, ON, L8S 4K1, Canada.
Allan
Damon A
DA
Tarnopolsky
Mark A
MA
Tiidus
Peter M
PM
Phillips
Stuart M
SM
D001707:Biopsy, Needle; D003402:Creatine Kinase / Q000097:blood; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D009119:Muscle Contraction / Q000502:physiology*; D018763:Muscle Fatigue / Q000502:physiology*; D018482:Muscle, Skeletal / Q000473:pathology* / Q000502:physiology*; D009751:Nutritional Requirements; D019415:Torque; D014810:Vitamin E / Q000008:administration & dosage* / Q000494:pharmacology*
D014810:Vitamin E; D003402:Creatine Kinase