Chronic ingestion of a low dose of caffeine induces tolerance to the performance benefits of caffeine

This study examined effects of 4 weeks of caffeine supplementation on endurance performance. Eighteen low-habitual caffeine consumers (<75 mg · day−1) were randomly assigned to ingest caffeine (1.5–3.0 mg · kg−1day−1; titrated) or placebo for 28 days. Groups were matched for age, body mass, V̇O2peak and Wmax (P > 0.05). Before supplementation, all participants completed one V̇O2peak test, one practice trial and 2 experimental trials (acute 3 mg...