Sleep specialist says wait 90 minutes before your first caffeine hit
If your morning routine begins with a hot cup of coffee, it might be time to reassess your daily habits. A leading sleep expert has revealed there is indeed a “perfect time” to drink caffeine – and it’s not as soon as you wake up.
Dr Michael Breus shared this insight during his guest appearance on The Diary of a CEO podcast with Steven Bartlett. “Did you know there’s like a perfect time to have coffee?” he said, explaining that the best timing is partially dictated by your chronotype, or natural sleep-wake cycle.
He then posed a common question: “Is the first liquid that crosses over your lips in the morning caffeinated?” When Bartlett admitted that it was, Dr Breus responded: “Let’s talk about why that’s probably not the best idea.”
Sleep itself is a dehydrating process, with Dr Breus stating that a person can lose close to a litre of water overnight simply through breathing. The NHS notes that fluids are lost daily through breathing, sweating and urination, highlighting the importance of staying hydrated to support normal bodily functions.
Dr Breus also pointed out that caffeine acts as a diuretic, meaning it increases urine production. The Mayo Clinic confirms caffeine can have a mild diuretic effect, although regular coffee drinkers may develop some tolerance over time.
Embed from Getty Images
According to the sleep specialist, the ideal time to drink your morning coffee is approximately 90 minutes after waking. “In order to exit a state of unconsciousness, you need two hormones – adrenaline and cortisol,” he explained, noting that both naturally spike in the morning to help the body wake up.
“When you have a brain that’s full of adrenaline and cortisol and you add caffeine to it, it’s like adding weak tea to somebody who’s taking cocaine,” he said.
Dr Breus recommends waiting for those hormone levels to decline slightly before having coffee. By doing so, caffeine may have a stronger and more noticeable effect, potentially allowing people to feel more alert with less consumption.
“So you hydrate before you caffeinate,” he advised, suggesting between 15 and 20 ounces of water, roughly three to four cups, during the first 90 minutes after waking.
The British Nutrition Foundation advises most adults to aim for six to eight glasses of fluid daily, including water, to maintain adequate hydration.
When it comes to safe caffeine intake, the European Food Safety Authority states that up to 400mg of caffeine per day, around four cups of coffee, is generally considered safe for healthy adults. Exceeding that amount can lead to symptoms such as anxiety, disrupted sleep, increased heart rate and digestive discomfort.
Too little caffeine may cause headaches or fatigue in regular coffee drinkers due to mild withdrawal, experts warn. However, Dr Breus suggests that optimising the timing could result in increased alertness with less coffee – simply by delaying that crucial 90 minutes.