I’ve written about sleep before and shortly mentioned why it’s important to avoid stimulants in the evening. However, since one of my projects for this year is to get better sleep, I thought I’d share a study investigating caffeine consumption 0, 3 and 6 hours before going to sleep.
Drake and his research team studied 12 healthy normal sleepers, as determined by a physical examination and clinical interview. Participants were instructed to maintain their normal sleep schedules.
They were given three pills a day for four days, taking one pill at six, three and zero hours prior to scheduled bedtime. One of the pills contained 400 mg of caffeine, and the other two were a placebo. On one of the four days, all three pills were a placebo. Sleep disturbance was measured subjectively with a standard sleep diary and objectively using an in-home sleep monitor.
Results show that 400 mg of caffeine (about 2–3 cups of coffee) taken at bedtime, three and even six hours prior to bedtime significantly disrupts sleep. Even when caffeine was consumed six hours before going to bed, objectively measured total sleep time was dramatically reduced (more than one hour). However, subjective reports suggest that participants were unaware of this sleep disturbance.
I regularly use caffeine in the morning to boost performance during my workout and it’s also listed under recommended supplements but you need to know when to use it.
This study showed that even when caffeine was consumed as early as six hours before going to bed, sleep time was dramatically reduced. So, if you’re considering sleeping at 23:00, you probably shouldn’t consume caffeine after 17:00. Personally I never consume it after 12:00.
If you’re considering purchasing caffeine, I use and recommend Caffeine 200 Big Buy.