+ 15 % en 4 semaines
Effect of Magnesium Supplementation in Isokinetic Knee-Flexion in Elite Volleyball Player
Medicine & Science in Sports & Exercise:Volume 40(5) Supplement 1May 2008p S341
Setaro, Luciana1; D'A.Greve, Julia M.1; Nakano, Eduardo Y.2; Correia, Fabio3; Colli, Celia1
1University of S. Paulo, São Paulo, Brazil. 2University of Brasilia, Brasilia, Brazil. 3Santander Sport Club, São Bernardo do Campo, Brazil.
Magnesium is involved in various processes that affect muscle function including energy production and electrolyte balance. The relationship between magnesium status and exercise has received significant attention in the past decade, and supplementation, in order to improve performance, is a discussed subject.
PURPOSE: To evaluate if magnesium supplementation improves muscle strength in well trained athletes.
METHODS: Nine male athletes (23+2yrs), from a professional volleyball adult team, were randomly assigned to two experimental groups, double-blind: magnesium supplementation (500mg magnesium oxide capsules per day, five athletes) and control (500mg maltodextrin capsules per day, four athletes) during a four-week period. At t=0 and t=30days the athletes performed maximal eccentric isokinetic muscle actions of the dominant and nondominant knee extensor muscles at 60 degrees x s(-1) on a isokinetic dynamometer (Biodex).
RESULTS: After the experimental period the supplemented group had left and right knee flexion peak torque greater than the control (196+19 vs. 170+13N·m, p=0.06) and (202+19 vs. 176+20N·m, p=0.11) respectively.
CONCLUSIONS: The magnesium supplementation indicates an increase in the performance when evaluated for isokinetic knee-flexion. These differences had statistical significance (at the 0.15 level of significance), what recommends an evaluation with a larger sample.