Your caffeine use throughout the day could be contributing to poor sleep quality at night — meaning that you need more coffee the next morning, and the cycle continues. A study in 2013 looked at how consuming caffeine zero, three, or six hours prior to bedtime affected sleep quality, and discovered something surprising. While caffeine consumed just as the subjects went to sleep obviously made them wakeful and restless, coffee doses six hours before — say, at 4 p.m. when they were going to bed at 10 p.m. — kept them awake too.
“Caffeine taken six hours before bedtime has important disruptive effects on sleep,” the researchers wrote in the study. This, they explained, “provides empirical support for sleep hygiene recommendations to refrain from substantial caffeine use for a minimum of six hours prior to bedtime.” Check out your usual coffee and tea schedule and cut out the afternoon doses if they come within that six-hour window.