Staying healthy is so easy, right? Log eight hours of sleep, work out for an hour a day at least five days a week, and steer clear of processed foods. But that math doesn’t always add up—trying to fit in the recommended dosage of sleep and exercise, on top of all the other variables in your life (kids! work! relationships!), can seem impossible. So when you’re debating the choice of lying in bed for another two hours or dragging yourself to the gym, sometimes shuteye wins.
But is that such a bad thing? After all, some mornings you just don’t feel well, or maybe you overdid it yesterday. Turns out, science still doesn’t have the hard and fast answer. “Both sleep and exercise are main behaviours that contribute to physical and mental health,” says Dr. Kelly Glazer Baron, a clinical psychologist and sleep researcher at the Feinberg School of Medicine at Northwestern University. Her research has found that clocking at least seven hours of sleep can actually help you work out longer and harder the next day. And the exercise/sleep equation goes both ways—people with insomnia who started a regular aerobic exercise program improved the quality of their sleep and felt less tired during the day, another study from Northwestern University found.
Considering multiple studies point to the direct relationship between sleep and exercise, there’s no denying that you should strive for adequate amounts of both. That said, there are still a few hard and fast rules you can follow to determine what to do on those tough days when your bed feels oh-so-comfy.
If you got seven to eight hours of sleep the night before… You’re good to hit the gym, says Fable. Seven to nine hours of sleep is what most adults need, according to the National Sleep Foundation.