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http://www.eurojournals.com/rjis_9_06.pdf Eipä juuri sinkki lisillä nähtävästi voiman suhteen lisäystä tämän tutkimuksen mukaan.
e. Kun taas toisessa tutkimuksessa saatu aivan päin vastaisia tuloksia NÄIN
ZMA lisää annetun ryhmän kokonais testosteroni nousi 567.92 -> 752.17 ng/ml kun placebo ryhmällä 588.80 -> 526.80 ng/ml ja vapaa testosteroni ZMA ryhmällä 132.10 -> 176.34 ng/ml ja placebo ryhmällä 141.02 -> 126.53 ng/ml.
Jipii. Yksi tutkimus.
Sinkistä on apua, jos siitä on puutetta. Syömällä sinkkirikkaita ruokia saa vähän muutakin kuin sinkkiä.
Am J Clin Nutr. 2000 Aug;72(2 Suppl):585S-93S.
Magnesium, zinc, and chromium nutriture and physical activity.
Lukaski HC.
US Department of Agriculture, Agricultural Research Service, Grand Forks Human Nutrition Research Center, Grand Forks, ND 58202-9034, USA. hlukaski@gfhnrc.ars.usda.gov
Magnesium, zinc, and chromium are mineral elements required in modest amounts to maintain health and optimal physiologic function. For physically active persons, adequate amounts of these micronutrients are needed in the diet to ensure the capacity for increased energy expenditure and work performance. Most physically active individuals consume diets that provide amounts of magnesium and zinc sufficient to meet population standards. Women tend to consume less of these minerals than is recommended, in part because they eat less food than men. Inadequate intakes of magnesium and zinc have been reported for participants in activities requiring restriction of body weight. Dietary chromium is difficult to estimate because of a lack of appropriate reference databases. Acute, intense activity results in short-term increases in both urine and sweat losses of minerals that apparently diminish during recovery in the days after exercise. Supplemental magnesium and zinc apparently improve strength and muscle metabolism. However, evidence is lacking as to whether these observations relate to impaired nutritional status or a pharmacologic effect. Chromium supplementation of young men and women does not promote muscle accretion, fat loss, or gains in strength. Physically active individuals with concerns about meeting guidelines for nutrient intake should be counseled to select and consume foods with high nutrient densities rather than to rely on nutritional supplements. The indiscriminate use of mineral supplements can adversely affect physiologic function and impair health.
Eur J Clin Nutr. 2009 Jan;63(1):65-70. Epub 2007 Sep 19.
Serum testosterone and urinary excretion of steroid hormone metabolites after administration of a high-dose zinc supplement.
Koehler K, Parr MK, Geyer H, Mester J, Schänzer W.
Institute of Biochemistry, German Research Centre of Elite Sport, German Sport University Cologne, Cologne, Germany. k.koehler@biochem.dshs-koeln.de
OBJECTIVES: To investigate whether the administration of the zinc-containing nutritional supplement ZMA causes an increase of serum testosterone levels, which is an often claimed effect in advertising for such products; to monitor the urinary excretion of testosterone and selected steroid hormone metabolites to detect potential changes in the excretion patterns of ZMA users. SUBJECTS: Fourteen healthy, regularly exercising men aged 22-33 years with a baseline zinc intake between 11.9 and 23.2 mg day(-1) prior to the study. RESULTS: Supplementation of ZMA significantly increased serum zinc (P=0.031) and urinary zinc excretion (P=0.035). Urinary pH (P=0.011) and urine flow (P=0.045) were also elevated in the subjects using ZMA. No significant changes in serum total and serum free testosterone were observed in response to ZMA use. Also, the urinary excretion pattern of testosterone metabolites was not significantly altered in ZMA users. CONCLUSIONS: The present data suggest that the use of ZMA has no significant effects regarding serum testosterone levels and the metabolism of testosterone in subjects who consume a zinc-sufficient diet.