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

20.08.2023

210 or 420 milligrams - which dose of caffeine works better?

When trained cyclists take a reasonable dose of caffeine of about 210 milligrams, they ride faster than after taking twice that dose. Australian researchers at Griffith University came to this somewhat paradoxical conclusion in a human study that was published in 2011 in the Journal of Sports Sciences.

Study
Griffith University's Ben Desbrow asked 16 male cyclists to cut out coffee and other caffeinated foods for 24 hours before an experimental time trial. [J Sports Sci. 2012;30(2):115-20.] The riders then reported to the lab, were given a light breakfast, mainly carbohydrates - and then had to cycle for about 60 minutes.

Desbrow had calculated for each runner how much work they could theoretically do if they could run at 75 percent of their maximum oxygen uptake for 60 minutes. Then, during a time trial, Desbrow looked at how long it took the riders to do this amount of work.

Just before and twice during their time trial, the riders were given a sports drink with quickly absorbable carbohydrates.

Desbrow performed this procedure 3 times. One time they took a placebo 90 minutes before their session, the other time a dose of 3 milligrams of caffeine per kilogram of body weight and another time a dose of 6 milligrams of caffeine per kilogram of body weight.

Results
The figure below shows the concentration of caffeine in the cyclists' blood. It was almost at his highest level when the time trial started. When the time trial was over, he was a bit higher.

Textbooks often give the impression that the concentration of caffeine in the blood peaks 45-60 minutes after ingestion. That's not what you would expect when you see the chart below.

The table above [click on it for a larger version] shows that both doses of caffeine reduced the runners' times. It also shows that the relatively low dose - you can ingest it with 2 cups of strong coffee - worked better than the double dose.

Other research results
In quite a few other similar studies, researchers conclude that higher doses of caffeine actually work better than lower ones. The figure below comes from one such study. We found it in the graduation thesis of James Martin, a sports scientist who obtained his PhD in 2009 from James Madison University in the US. [Martin, Michael. The effects of different doses of caffeine on a 40 kilometer cycling time trial: A dose-response study. (2009). Masters Theses, 2010-2019. 267.]

Like Desbrow, Martin compared the effect of 3 milligrams of caffeine per kilo of body weight with that of 6 milligrams of caffeine per body weight.

There are a number of differences in the experimental design that we, the stupid and ignorant compilers of this free web magazine, find interesting. We mention 2.

Desbrow gave his test subjects breakfast before letting them cycle and provided them with a sports drink during the session. Desbrow administered the supplement 90 minutes before the time trial. Martin got his subjects to cycle sober and administered the supplement 60 minutes before the time trial.

Perhaps the optimal dose of caffeine depends on carbohydrate administration. If you use carbohydrates, this optimal dose may be lower lower. However, if you add carbohydrates, the time it takes for caffeine to get into the blood may also be longer. Longer perhaps than the 45-60 minutes you find in the manuals.

Consensus
In 2021, the International Society of Sports Nutrition published a position paper on the use of caffeine in sports. [J Int Soc Sports Nutr. 2021 Jan 2;18(1):1.]

The compilers of that paper read no less than 420 scientific articles about caffeine and sports, but did not arrive at an unambiguous optimal dose of caffeine. They state that the optimal dose of caffeine is probably somewhere between 3 and 6 milligrams of caffeine per pound of body weight. They can't get any more accurate than that.

Source:
J Sports Sci. 2012;30(2):115-20.

More:
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Combine caffeine with taurine for a faster sprint 07.12.2021
Caffeine takes the sting out of physical exertion without carbohydrates 04.12.2021
Relatively low and relatively high dose of caffeine equally effective for strength athletes 27.05.2019

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