Q: I’ve heard that drinking coffee first thing in the morning can interfere with my ability to feel awake and can lead to an afternoon energy crash. Is that true?
It’s an idea that has been popularized by online influencers: Avoid consuming caffeine for 90 to 120 minutes after waking up, they say, and you will perk up more naturally, thwart the dreaded afternoon slump and have better sleep.
Proponents explain the idea as if it’s supported by good evidence, with some people who have tried the method saying it has “been a game changer” for their energy levels.
But scientists who study the relationship between caffeine and sleep say that while there may be some benefits to putting off your morning coffee, there’s not much research to back them up.
In some cases, experts warn, the risks of delaying your morning caffeine could outweigh the purported benefits — or even be dangerous.
How Caffeine Works, and How Long It Lasts
Throughout the day, your body produces a chemical called adenosine, which binds to receptors in your brain and makes you feel drowsy. Caffeine perks you up by blocking those receptors, said Marilyn Cornelis, a caffeine researcher at the Northwestern University Feinberg School of Medicine.