You may already know that good sleep is associated with good health.
Getting your eight (or nine) hours, especially in middle age, has been associated with a reduced risk of dementia; it seems to be great for your heart too.
But a new study suggests that when you fall asleep may matter almost as much as how long you kip for.
Published in the Journal of Epidemiology and Community Health, the researchers found that even when people with an irregular sleep schedule got as many hour’s sleep as they needed, they were still more likely than people with a set sleep schedule to suffer various medical conditions.
Those with moderately irregular sleep patterns did benefit from having more sleep, though.
Scientists looked at data from 72,269 people aged 40 to 79 in the UK Biobank study.
The participants wore activity trackers that recorded their sleep duration and start and end times.
The researchers found that people who didn’t get to sleep or wake up at roughly the same time every day were at a 26% higher risk of heart attack, stroke, and heart failure ― even if they got enough sleep.
Those with a moderately irregular sleep schedule were at an 8% higher risk.
The further away from a “set” sleep and rise point you were, the more likely those conditions seemed to be.
The study’s lead author, Jean-Philippe Chaput, told The Guardian that we should try to stick to within 30 minutes of wake and sleep times, including weekends.
“Within an hour of the same time is good but less good than 30 minutes, and even better is to have zero variation,” he added.
Waking up at the same time every day seemed more important than falling asleep at the same time, the researcher continued.
“If you need to catch up on sleep you’ve missed during the week at weekends, then going to bed earlier is better than lying in – you should still be trying to wake up at the same time, even on Saturdays and Sundays.”
The researcher said that veering away from your schedule for more than an hour has been associated with a higher risk of developing certain health conditions.
The Mayo Clinic recommends the following steps to set a good sleep schedule: