How caffeine acts as an ergogenic aid
Caffeine primarily blocks adenosine receptors in the central nervous system, reducing perceived effort and fatigue. This central effect, along with smaller influences on muscle and substrate use, is why caffeine improves outcomes across endurance, strength, sprint, and reaction-time tasks rather than only one domain.
Commonly studied doses fall around 3 to 6 mg per kg of bodyweight, taken roughly 30 to 60 minutes before activity to align with absorption. Higher doses rarely add benefit and increase side effects like jitter, elevated heart rate, and disrupted sleep.
Why genotype and habituation shift the response
Variation in the CYP1A2 gene affects how quickly caffeine is metabolized, which may shift where an individual sits on the dose-response curve. Habitual intake and sensitivity also move the optimal amount, so the curve is a population average, not a personal prescription.
This is general educational information, not medical advice. Caffeine can be unsafe at high intakes and interacts with some medications and conditions, including anxiety and cardiac issues. Consult a qualified professional before using it strategically, especially in larger doses.