No effects of short-term vitamin E supplementation on inflammatory and muscle damage markers after repeated bouts of prolonged exercise in healthy young men

After a single bout of prolonged strenuous exercise, inflammatory and muscle damage markers increase. The present study investigated whether vitamin E supplementation can attenuate inflammatory (C-reactive protein (CRP) and interleukin-6 (IL-6)) and muscle damage (creatine kinase (CK) and lactate dehydrogenese (LDH)) markers after prolonged repeated bouts of cycling in healthy young men. Eight young males (aged 21-30 y) were received both vitamin E supplement (300 mg/day) and placebo (control) for 14 days separated by at least an interval of 1 month in a randomised, counterbalanced design. On day 12 of both trials, subjects cycled at 80% of maximal heart rate in two, 90-min bouts (150 min rest between each). Blood samples were collected on days 1 (baseline), 12 (pre- and post-exercise 1 and pre- and post-exercise 2), 13, 14, and 15. After 14 days of supplementation, serum α-tocopherol concentrations increased in the vitamin E trial (P<0.0005) but not the placebo trial. Serum CRP concentrations did not differ between trials and did not significantly change over the observation period in both trials. Serum IL-6, CK, and LDH concentrations increased (P≤0.024) in response to repeated bouts of exercise in both trials but did not differ between trials. The study demonstrates that short-term vitamin E supplementation appears to have no effect on attenuating markers of inflammatory and muscle damage in response to repeated bouts of prolonged exercise in healthy young men.