Caffeine for exercise performance (acute dosing)

What this protocol is

Acute caffeine supplementation means a timed dose before or during a session to study exercise performance (capsules, gum, or coffee in trials). Dose (commonly ~3–6 mg/kg in research), timing (often ~30–60 min pre-exercise), habitual vs low consumers, and delivery form are within-family variation—kept under one slug so users do not lose meta-analytic evidence behind “anhydrous capsule” vs “espresso” branding.

Umbrella synthesis (PubMed-first)

Grgic et al. 2020 (Br J Sports Med; PMID 30926628; grgic-2020-caffeine-exercise-umbrella-bjsm) synthesised 11 systematic reviews (21 meta-analyses): caffeine was ergogenic for aerobic endurance, muscle strength, muscle endurance, power, jumping performance, and exercise speed in pooled models, with GRADE often moderate (some domains low–very low). Authors note 95% prediction intervals did not always exclude null for every pooled endpoint—read primary tables before treating every subdomain as uniformly proven.

Society position stand (dose, timing, genetics)

Guest et al. 2021 (J Int Soc Sports Nutr.; PMID 33388079; guest-2021-issn-caffeine-exercise-position-stand) — ISSN expert review aligning with the umbrella direction while spelling out 3–6 mg/kg typical research doses, ~60 min pre-exercise timing (vehicle-dependent), genetics / habitual intake drivers of variable response, and heat / altitude dosing bands cited in the abstract—read COI declarations alongside Grgic tables.

CYP1A2 genotype stratification (performance meta-analysis)

Barreto et al. 2023 (Med Sci Sports Exerc; PMID 37844569; barreto-2023-caffeine-cyp1a2-genotype-exercise-performance-meta-mss) performed three-level meta-analyses stratified by CYP1A2 rs762551: pooled models report ergogenic caffeine effects in AA and AC genotypes but statistically worse performance on caffeine versus placebo in CC homozygotes at typical study doses, with dose / timing / conflict-of-interest meta-regressions shifting CC-stratum estimates—read discussion caveats on genotyping coverage and placebo-arm balance before using genotypes as triage rules in sport.

Evidence hygiene

• Population: most underlying trials enrolled young men—generalisation to women, midlife, and masters athletes needs more primary studies (as the umbrella discussion stresses).
• Aerobic vs anaerobic framing: the umbrella’s narrative suggests larger typical pooled effects for aerobic endurance than for some anaerobic domains—still read forest plots per outcome.
• Safety / clinical context: anxiety, arrhythmia, GERD, pregnancy, and medication interactions (e.g., some adenosine-receptor–active drugs) are reasons to involve clinicians; this wiki summarises performance literature, not individual stimulant tolerance.

Distinct protocols (do not merge)

• Creatine monohydrate (creatine-monohydrate-supplementation) — phosphocreatine / intramuscular stores; chronic loading models differ from single-dose caffeine pharmacokinetics.
• Time-restricted eating (time-restricted-eating) / intermittent fasting (intermittent-fasting) — meal-window metabolic trials; black coffee outside a window is not the same evidence stream as pre-lift caffeine RCTs.
• Resistance training (resistance-training) — program design; caffeine rows here complement, not replace, volume–frequency evidence.

Tertiary map

Wikipedia: Caffeine (wikipedia-caffeine-overview) covers mechanism, half-life, content in beverages, and toxicity vocabulary—pooled performance SMDs / GRADE belong to the PubMed-linked umbrella row here.