קטגוריה: תזונת ספורט
אומגה 3 משפרת ביצועי ספורטאים ומונעת מחלות ספורט
Omega-3 Fatty Acids and Athletics Artemis P. Simopoulos, MD Current Sports Medicine Reports 2007, 6:230–236 Current Medicine Group LLC ISSN 1537-890x
Human beings evolved consuming a diet that contained about equal amounts of n-6 and n-3 essential fatty acids. Today, in Western diets, the ratio of n-6 to n-3 fatty acids ranges from approximately 10:1 to 20:1 instead of the traditional range of 1:1 to 2:1.
Studies indicate that a high intake of n-6 fatty acids shifts the physiologic state to one that is prothrombotic and proaggregatory, characterized by increases in blood viscosity, vasospasm, and vasoconstriction, and decreases in bleeding time. ?-3 fatty acids, however, have anti-inflammatory, antithrombotic, antiarrhythmic, hypolipidemic, and vasodilatory properties.
Excessive radical formation and trauma during high-intensity exercise leads to an inflammatory state that is made worse by the increased amount of n-6 fatty acids in Western diets, although this can be counteracted by eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).
For the majority of athletes, especially those at the leisure level, general guidelines should include EPA and DHA of about 1 to 2 g/d at a ratio of EPA:DHA of 2:1.
ביצועים ספורטיבים וויטמין D
Athletic Performance and Vitamin D JOHN J. CANNELL1, BRUCE W. HOLLIS2, MARC B. SORENSON3, TIMOTHY N. TAFT4, and JOHN J. B. ANDERSON5
1Atascadero State Hospital, Atascadero, CA; 2Departments of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC; 3sunlightandhealth.org, Saint George, UT; 4Departments of Orthopedics and Sports Medicine, University of North Carolina, Chapel Hill, NC; and 5Departments of Public Health and Nutrition, University of North Carolina, Chapel Hill, NC
ABSTRACT
CANNELL, J. J., B. W. HOLLIS, M. B. SORENSON, T. N. TAFT, and J. J. ANDERSON.
Athletic Performance and Vitamin D. Med.Sci. Sports Exerc., Vol. 41, No. 5, pp. 1102–1110, 2009.
Purpose: Activated vitamin D calcitriol) is a pluripotent pleiotropic secosteroid hormone. As a steroid hormone, which regulates more than 1000 vitamin D–responsive human genes, calcitriol may influence athletic performance. Recent research indicates that intracellular calcitriol levels in numerous human tissues, including nerve and muscle tissue, are increased when inputs of its substrate, the prehormone vitamin D, are increased.
Methods: We reviewed the world’s literature for evidence that vitamin D affects physical and athletic performance.
Results: Numerous studies, particularly in the German literature in the 1950s, show vitamin D–producing ultraviolet light improves athletic performance. Furthermore, a consistent literature indicates physical and athletic performance is seasonal; it peaks when 25-hydroxy-vitamin D [25(OH)D] levels peak, declines as they decline, and reaches its nadir when 25(OH)D levels are at their lowest. Vitamin D also increases the size and number of Type II (fast twitch) muscle fibers. Most cross-sectional studies show that 25(OH)D levels are directly associated with musculoskeletal performance in older individuals. Most randomized controlled trials, again mostly in older individuals, show that vitamin D improves physical performance.
Conclusions: Vitamin D may improve athletic performance in vitamin D–deficient athletes. Peak athletic performance may occur when 25(OH)D levels approach those obtained by natural, full-body, summer sun exposure, which is at least 50 ngImLj1. Such 25(OH)D levels may also protect the athlete from several acute and chronic medical conditions.
Key Words: PHYSICAL PERFORMANCE, PEAK ATHLETIC PERFORMANCE, ACTIVATED VITAMIN D, CALCITRIOL, 1, 25-DIHYDROXY-VITAMIN D, 25(OH)D