title: Association Between Vitamin D Status and Maximal-Intensity Exercise Performance in Junior and Collegiate Hockey Players.
abstract: Recent evidence suggests that athletes are at risk for poor vitamin D status. This study used a cross-sectional design to investigate the strength of association between 25-hydroxyvitamin D (25(OH)D) concentration and measures of maximal-intensity exercise performance in competitive hockey players. Fifty-three collegiate and junior male ice hockey players training near Minneapolis, MN (44.9° N latitude) participated in the study during the off-season (May 16-June 28). Circulating 25(OH)D concentration, grip strength, vertical jump performance, and power production during the Wingate Anaerobic Test (WAnT) were evaluated. Despite no athletes with 25(OH)D concentration indicative of deficiency (<20 ng·mL), positive bivariate correlations were detected between vitamin D status, relative grip strength (p = 0.024), and peak power during the WAnT (p = 0.035). Only for relative grip strength (p = 0.043), did 25(OH)D concentration predict performance after adjusting for level of play, fat-free mass, fat mass, and self-reported total physical activity in sequential linear regression. Vitamin D status was positively associated with starting gradient (p = 0.020) during the squat jump, with higher concentrations associated with increased rate of force development in the initial portion of the jump. Interventional trials should investigate the impact of vitamin D supplementation on maximal-intensity exercise performance outcomes and rate of force development in large samples of vitamin D-deficient athletes while controlling for training exposure. Our data indicate that if vitamin D status is causally related to maximal-intensity exercise performance in athletes, the effect size is likely small.
authors: 1Human Performance Laboratory, Department of Kinesiology and Public Health Education, University of North Dakota, Grand Forks, North Dakota; 2Human and Sports Performance Laboratory, School of Kinesiology, University of Minnesota, Minneapolis, Minnesota; and 3Department of Exercise Physiology, College of St. Scholastica, Duluth, Minnesota.
authors: John S
authors: JS
authors: Fitzgerald
authors: Ben J
authors: BJ
authors: Peterson
authors: Joseph M
authors: JM
authors: Warpeha
authors: Sam C
authors: SC
authors: Johnson
authors: Stacy J
authors: SJ
authors: Ingraham
mesh_terms: D054874:Athletic Performance / Q000502:physiology*; D015415:Biomarkers / Q000097:blood; D003430:Cross-Sectional Studies; D005080:Exercise Test; D006688:Hockey / Q000502:physiology*; D006801:Humans; D016014:Linear Models; D008297:Male; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000175:diagnosis / Q000503:physiopathology*; D055815:Young Adult
chemical_list: D015415:Biomarkers; D014807:Vitamin D; C104450:25-hydroxyvitamin D