Definition: "An ergogenic aid is any substance or phenomenon that enhances performance "

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Citrulline makes cyclists 1.5 percent faster

Cyclists can cycle four kilometres faster if they take a supplement containing L-citrulline, write researchers at the Japanese raw materials manufacturer Kyowa Hakko Bio in the Journal of the International Society of Sports Nutrition. The dose that the Japanese needed was modest to say the least: 2.4 gram L-citrulline per day. That's perfectly possible.

L-Citrulline is converted in the body into L-arginine, an amino acid that is a source of nitrogen monoxide. Muscle cells work better during pretty much every type of exertion the more nitrogen monoxide there is in the body.

To read more about the advantages of L-citrulline supplementation related to L-arginine click here.

The researchers got 22 trained cyclists to cycle a distance of four kilometres in as short a time as possible, on two different occasions. On the one occasion the cyclists took a placebo daily; on the other they took 2.4 g L-citrulline daily.

On the day of the time trial the cyclists took the amino acid an hour before getting on their bikes.

The L-citrulline supplementation, as you might expect, boosted the concentration of nitrogen monoxide [NOx] in the participants' blood. And that improved the functioning of the muscles, again as you would expect. The supplementation reduced by 1.5 percent the amount of time it took the participants to complete the four kilometres.

Citrulline makes cyclists 1.5 percent faster

Citrulline makes cyclists 1.5 percent faster

On the right above you can see that L-citrulline increased the participants' power. So the amino acid enabled them to cycle faster.

The participants reported less fatigue after cycling when they had taken the L-citrulline supplement than when they cycled on a placebo. The amino acid did reduce their concentration though. [Perhaps an argument for combining L-citrulline with a mild stimulant such as caffeine? - Ed.]

"These data, taken together, suggest that L-citrulline is a promising amino acid for enhancing sport performance", the researchers wrote.

J Int Soc Sports Nutr. 2016 Feb 19;13:6.

Cyclists on L-citrulline use more amino acids 06.10.2010
Supplement with L-arginine and L-citrulline makes cyclists faster 20.04.2010

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