n South African Journal of Sports Medicine - The effects of an L-methionine combination supplement on symptoms of upper respiratory tract infections and performance in ultramarathon runners before, during and after ultra-endurance exercise : original research article
|Article Title||The effects of an L-methionine combination supplement on symptoms of upper respiratory tract infections and performance in ultramarathon runners before, during and after ultra-endurance exercise : original research article|
|© Publisher:||Health and Medical Publishing Group (HMPG)|
|Journal||South African Journal of Sports Medicine|
|Author||L.M. Harden, N. Neveling, F. Rossouw, S.J. Semple, F.E. Marx, J. Rossouw and G. Rogers|
|Publication Date||Apr 2004|
|Pages||10 - 16|
<I>Objective.</I> To evaluate whether supplementation with an L-methionine combination would reduce the incidence of upper respiratory tract symptoms (URTS) and improve performance in ultramarathon runners. <br><I>Design.</I> A double-blind placebo-controlled study. <br><I>Setting.</I> Twenty-one ultramarathon runners (17 males, 4 females) preparing for participation in an 87.3 km ultramarathon. <br><I>Interventions.</I> L-methionine combination supplement (L-methionine, vitamin B<sub>6</sub>, vitamin B<sub>12</sub>, folic acid and magnesium) or placebo containing potato starch. <br><I>Main outcome measures.</I> Incidence of URTS was recorded during the runner's preparation for an ultramarathon race (75 days) and recovery from the same (75 days). CD4+, CD8+ cell counts and ratios were measured pre race, immediately post race and 75 days post race. VO<sub>2max</sub> and endurance fitness (percentage VO<sub>2max</sub> at 4 mmol<sup>-1</sup> lactate concentration) were measured during the preparation period for the race. <br><I>Results.</I> During the preparation period the incidence of URTS was 36% in the supplement group and 80% in the placebo group (<I>p</I> = 0.08). The incidence of URTS during the 3 weeks post race was 27% in the supplement group and 40% in the placebo group (<I>p</I> = 0.65). The CD4+/CD8+ cell ratios were not significantly different between groups. Endurance fitness prior to the race and race times were not significantly different. <br><I>Conclusions.</I> Although the findings of the current study show that an L-methionine combination supplement did not reduce the incidence of URTS or improve performance in ultramarathon runners, benefits may be found with a more detailed investigation using larger sample sizes and immunosuppressed athletes.
Article metrics loading...