Caffeine

Form: Caffeine anhydrous or coffee

Typical dose studied: 3–6 mg/kg body weight

Timing: 30–60 minutes before exercise or cognitive task

Test caffeine during training — not for the first time on competition day. Guarana (Paullinia cupana) is essentially a concentrated caffeine source (seeds run up to ~6% caffeine by weight, roughly double coffee beans) plus theobromine and polyphenols — treat any guarana product as a caffeine source for dosing-limit and interaction purposes, since its stimulant effect is largely caffeine's effect. The main practical issue is that guarana products often don't disclose actual caffeine content, so track total intake conservatively rather than assuming a guarana serving is caffeine-free.

Avoid with: Generalized anxiety disorder; Primary hypertension / High blood pressure; Breastfeeding

Interacts with: Stimulants; Certain psychiatric medications

Already taking it? Monitor total daily intake — stay under 400 mg/day for most healthy adults. Limit intake further in pregnancy -- worth stating plainly even though the platform's own intake flow already hard-blocks recommendation generation for anyone reporting current pregnancy.

ISSN Position Stand: Caffeine. IOC Consensus Statement on Caffeine. Grgic J et al. Caffeine meta-analysis.