When should I take caffeine before a race?

Peak plasma levels occur roughly 45 to 60 minutes after ingestion. For a race starting at 7:00 AM, take your pre-race dose at 6:00 to 6:15 AM. Taking it too early or too late shifts the performance window away from the hardest effort.

Can I take caffeine mid-race?

Yes. Caffeinated gels with 25 to 50 mg are effective for top-ups during long events. The goal is to sustain elevated plasma caffeine without exceeding 400 mg total. Space mid-race doses at least 45 minutes apart to allow absorption.

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Caffeine Calculator for Endurance Athletes

Q: How much caffeine should I take before a race?

The evidence-based pre-race dose is 3 to 6 mg per kilogram of body weight, taken 45 to 60 minutes before the start. A 70 kg athlete would take 210 to 420 mg. Start at the lower end if you are caffeine-sensitive or have not tested it in training.

Q: Does caffeine improve endurance performance?

Yes. Multiple meta-analyses show caffeine improves endurance performance by 2 to 4 percent on average. The effect is most pronounced in events lasting 30 minutes to 3 hours. It works by blocking adenosine receptors, reducing perceived effort and improving fat oxidation at threshold intensity.

Dial in your race-day caffeine dose and timing without the jitters or the late-race crash. Enter your event and body weight to get a starting protocol grounded in the ISSN position stand. We call the output your Race-Day Caffeine Protocol.

EB says

120 mg

Caffeine

Per International society of sports nutrition position stand: caffeine and exercise performance (Journal of the International Society of Sports Nutrition (Guest et al., 2021))

Step 2: Your caffeine plan

Enter your details and hit calculate. Your plan appears here and the URL updates so you can bookmark or share it.

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Does caffeine dehydrate you during a race?

No. The idea that caffeine dehydrates athletes is a myth from old resting studies. At the moderate doses endurance athletes use (about 3 to 6 mg per kg of body weight), caffeine has only a mild, transient diuretic effect that disappears in habitual coffee drinkers, and exercise itself blunts it further. Controlled studies show no meaningful difference in hydration, sweat loss, or body-water balance between caffeinated and decaffeinated drinks during training.

The fluid in a caffeinated sports drink, gel, or coffee still counts toward your hydration. Plan your fluids around your sweat rate and the climate, not around the caffeine. The real downside of overdoing caffeine is a racing heart, jitters, and GI upset, not dehydration, which is why the dose, not the water, is the thing to dial in above. For the full breakdown of the myth and the research behind it, see does caffeine dehydrate you.

Common questions

How much caffeine should I take before a race?

3 to 6 mg per kg of body weight is the evidence-based performance range. A 70 kg athlete would take 210 to 420 mg. Consume your dose 45 to 60 minutes before the start for peak blood concentration.

Does caffeine improve endurance performance?

Yes. Meta-analyses consistently show caffeine improves endurance time-to-exhaustion by 10 to 15 percent and time-trial performance by 2 to 4 percent at doses of 3 to 6 mg per kg. It works by blocking adenosine receptors, which reduces perceived exertion and pain.

Should I abstain from caffeine before a race?

A 7 to 14 day abstinence window increases sensitivity, but recent evidence shows it is not required. Regular caffeine users still get a meaningful performance boost on race day. A 3 to 5 day taper before a key race is a practical middle ground.

See also: How to calculate your caffeine dose by weight and Caffeine timing for endurance athletes. Building your full race-day fuel plan? Pair this with the carbs per hour calculator and the sodium calculator.

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