%0 Journal Article
%T Vitamin D2 Supplementation Amplifies Eccentric Exercise-Induced Muscle Damage in NASCAR Pit Crew Athletes
%A David C. Nieman
%A Nicholas D. Gillitt
%A R. Andrew Shanely
%A Dustin Dew
%A Mary Pat Meaney
%A Beibei Luo
%J Nutrients
%D 2014
%I MDPI AG
%R 10.3390/nu6010063
%X This study determined if 6-weeks vitamin D 2 supplementation (vitD 2, 3800 IU/day) had an influence on muscle function, eccentric exercise-induced muscle damage (EIMD), and delayed onset of muscle soreness (DOMS) in National Association for Stock Car Auto Racing (NASCAR) NASCAR pit crew athletes. Subjects were randomized to vitD 2 ( n = 13) and placebo ( n = 15), and ingested supplements (double-blind) for six weeks. Blood samples were collected and muscle function tests conducted pre- and post-study (leg-back and hand grip dynamometer strength tests, body weight bench press to exhaustion, vertical jump, 30-s Wingate test). Post-study, subjects engaged in 90 min eccentric-based exercise, with blood samples and DOMS ratings obtained immediately after and 1- and 2-days post-exercise. Six weeks vitD 2 increased serum 25(OH)D 2 456% and decreased 25(OH)D 3 21% versus placebo ( p < 0.001, p = 0.036, respectively), with no influence on muscle function test scores. The post-study eccentric exercise bout induced EIMD and DOMS, with higher muscle damage biomarkers measured in vitD 2 compared to placebo (myoglobin 252%, 122% increase, respectively, p = 0.001; creatine phosphokinase 24 h post-exercise, 169%, 32%, p < 0.001), with no differences for DOMS. In summary, 6-weeks vitD 2 (3800 IU/day) significantly increased 25(OH)D 2 and decreased 25(OH)D 3, had no effect on muscle function tests, and amplified muscle damage markers in NASCAR pit crew athletes following eccentric exercise.
%K delayed onset of muscle soreness (DOMS)
%K myoglobin
%K creatine phosphokinase
%K muscle function testing
%K eccentric exercise
%K LC-MS/MS
%U http://www.mdpi.com/2072-6643/6/1/63