Quercetin förbättrar VO2max och uthållighet utan träning

[King Grub]

Quercetin, a natural polyphenolic flavonoid substance present in a variety of food plants, has been shown in vitro and in animal studies to have widespread health and performance benefits resulting from a combination of biological properties, including antioxidant and anti-inflammatory activity, as well as the ability to increase mitochondrial biogenesis. Little is known about these effects in humans, however, especially with respect to exercise performance. The authors determined whether quercetin ingestion would enhance maximal aerobic capacity and delay fatigue during prolonged exercise in healthy but untrained participants. Twelve volunteers were randomly assigned to 1 of 2 treatments: (a) 500 mg of quercetin twice daily dissolved in vitamin-enriched Tang or (b) a nondistinguishable placebo (Tang). Baseline VO2max and bike-ride times to fatigue were established. Treatments were administered for a period of 7 days using a randomized, double-blind, placebo-controlled, crossover study design. After treatment both VO2max and ride time to fatigue were determined. Seven days of quercetin feedings were associated with a modest increase in VO2max (3.9% vs. placebo; p < .05) along with a substantial (13.2%) increase in ride time to fatigue (p < .05). These data suggest that as little as 7 days of quercetin supplementation can increase endurance without exercise training in untrained participants. These benefits of quercetin may have important implications for enhancement of athletic and military performance. This apparent increase in fitness without exercise training may have implications beyond that of performance enhancement to health promotion and disease prevention.

Int J Sport Nutr Exerc Metab. 2010 Feb;20(1):56-62. The Dietary Flavonoid Quercetin Increases VO2max and Endurance Capacity.

http://hk.humankinetics.com/ijsnem/viewarticle.cfm?jid=jNcAGWxMhDnXDWT7rXcHEwRQpWwXQ2 McaBmUu3R3fNuYm8cJc&view=art&aid=17824&site=jNcAGWxMhDnXDWT7rXcHEwRQpWwXQ2McaBmUu3R3fNuYm 8cJc

[L-Sami]

Endast 12 försökspersoner deltog i studien och informerades de som fick Quercetin att de inte ska vara fysisk aktiva under behandlingstiden? Vilka var de som deltog i studien förutom att de var frivilliga?

[Tanner]

Endast 12 försökspersoner deltog i studien och informerades de som fick Quercetin att de inte ska vara fysisk aktiva under behandlingstiden? Vilka var de som deltog i studien förutom att de var frivilliga?

12 pers får väl anses bra när det är en träningsstudie...

Deras studiebeskrivning

A double-blind, placebo controlled, crossover study was used to examine the effects of 7 days of quercetin supplementation on maximal oxygen consumption (VO2max) and endurance capacity on healthy, ft but untrained participants

To be considered for inclusion, participants had to have a VO2max value greater than 35 ml · kg–1 · min–1 and not be currently involved in an aerobic exercise-training program. They were asked not to alter their diet or over-the-counter medications during the course of the study, especially during the 24 hr before exercise testing.


Så det är bara att byta ut rödbetsjuicen mot druvor nu :P

[Zorgus]

Tidigare studier har gett resultat åt båda hållen:

http://www.sciencedaily.com/releases/2009/09/090903110820.htm

Man kanske inte ska börja tokäta druvor ändå...

[King Grub]

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.

CONCLUSION:

Our findings suggest that supplementation with quercetin in athletes may improve some indices of performance.

Int J Prev Med. 2013 Jan;4(1):21-6. The effects of quercetin supplementation on body composition, exercise performance and muscle damage indices in athletes.

[maqan]

Hur mycket broccoli motsvarar 500 mg quercetin ungefär?