Research

Hormonal

Acute caffeine ingestion (6 mg/kg) significantly prolongs time to exhaustion during high-intensity exercise regardless of prior caffeine habituation or short-term withdrawal (0, 2, or 4 days).

If you are a habitual caffeine user, taking 6 mg/kg of caffeine about an hour before intense exercise (like cycling or running at 80-85% max effort) will likely extend your time to exhaustion. This benefit holds true whether you are currently consuming your normal amount of caffeine or have stopped for a few days. You do not need to 'wash out' caffeine to get the performance boost, although you should maintain your normal diet and avoid exercise the day before the event.

GoodSupportsHIGH confidence
Subjects responded to caffeine with increases in plasma epinephrine (P < 0.05) at exhaustion and prolonged exercise time in all caffeine trials compared with placebo, regardless of withdrawal from caffeine.
Mary H. van Soeren et al. · Journal of Applied Physiology · 1998

Why this rating

Double-blind, randomized, controlled trial with consistent results across withdrawal conditions, though small sample size (n=6).

Source

Effect of caffeine on metabolism, exercise endurance, and catecholamine responses after withdrawal

Mary H. van Soeren et al. · Journal of Applied Physiology · 1998

DOI 10.1152/jappl.1998.85.4.1493

rct · n=6Cited 186×
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DOI resolved against Crossref · corpus check 2026-06-10

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