no citation, no time for it, but for what its worth … approximately 1000 mg per day x 18 days leads to “complete” tolerence to the subjective effects of caffeine. Tapering off caffeine 2-3 weeks out will allow adenosine and other associated caffeine responsive receptors to regulate (read about up/down regulation) and hopefully minimize withdrawels (by tapering). Then race time receptors are fairly normalized and more responsive to caffeine…