title: The effects of quercetin supplementation on body composition, exercise performance and muscle damage indices in athletes.
abstract: BACKGROUND
  Flavonoids comprise a large group of plant metabolites, 6,000 of which have been identified to date. Some studies have shown the increased aerobic performance and maximal oxygen consumption (VO(2max)) and therefore fitness following quercetin intake as a result of elevated number of intracellular mitochondria caused by the flavonoid.
  
  
  METHODS
  This double-blind clinical trial comprised 60 male students having an athletic history of at least 3 years. Body composition, exercise performance, and some blood biomarkers were analyzed. The individuals were selected by convenient sampling, and then were assigned into four groups of equal number by using permuted block randomization. The first to fourth groups received a 500 mg supplemental quercetin capsule plus a 250 mg vitamin C pill, a 500 mg supplemental quercetin capsule plus a 250 mg placebo vitamin C pill, a 500 mg placebo quercetin capsule plus a 250 mg vitamin C pill, and a 500 mg placebo quercetin capsule plus a 250 mg placebo vitamin C pill, respectively, daily for 8 weeks. The participants were asked to continue their routine diet and physical activity during the study and they were monitored through phone calls or text messages.
  
  
  RESULTS
  Lean body mass, total body water, basal metabolic rate, and total energy expenditure increased significantly in the quercetin group after intervention. On the other hand, VO(2max) increased in the "quercetin" and "quercetin + vitamin C" groups following the intervention, non-significantly.
  
  
  CONCLUSIONS
  Our findings suggest that supplementation with quercetin in athletes may improve some indices of performance.
authors: Food Security Research Center, Isfahan University of Medical Sciences, Isfahan, Iran.
authors: Gholamreza
authors: G
authors: Askari
authors: Reza
authors: R
authors: Ghiasvand
authors: Zamzam
authors: Z
authors: Paknahad
authors: Jahangir
authors: J
authors: Karimian
authors: Katayoun
authors: K
authors: Rabiee
authors: Gholamreza
authors: G
authors: Sharifirad
authors: Awat
authors: A
authors: Feizi
keywords: Athletes; body composition; exercise performance; muscle damage; quercetin