Caffeine is a powerful stimulant that, when properly employed, can up our energy levels and productivity game significantly. Get too reliant, however, and it’ll be as bad as any addiction, with lessened effect. Dose strategically between 09:30-11:30 AM and 1:30- 5:00 PM, when your body’s cortisol levels drop, and you will most benefit from a boost.
Source: learn.filtered.com