Does daily coffee reduce caffeine's race-day benefit?

Habitual intake above roughly 300 mg per day attenuates the acute ergogenic response by around 30%. Whether a pre-race withdrawal helps is less clear than the folklore suggests.

Chronic caffeine consumption upregulates adenosine receptors, which blunts the acute effect of a given dose. Habitual intake above roughly 300 mg per day — about three cups of coffee — is associated with an attenuation of the ergogenic response on the order of 30%. Heavy daily users get less from race-day caffeine than occasional users do.

The obvious response is to abstain for a period before the race, and this is widely practised. The evidence for it is weaker than its popularity implies: several controlled studies find that habitual users still benefit from acute caffeine without any withdrawal period, and withdrawal itself produces headaches, irritability and reduced training quality in the days it matters most.

A reasonable middle position is to moderate rather than abstain. Bringing habitual intake down toward the lower part of the range over a couple of weeks preserves some sensitivity without a withdrawal crash in race week. Abruptly stopping three days out is the option with the worst risk-to-reward ratio.

It is also worth noting how large the individual variation is here. Some runners are highly sensitive regardless of habit; others get very little from caffeine at any dose. Your own experience across several races is a better guide than any population effect size.

Glossary: Caffeine Habituation, Caffeine