Sleep Length Myths: Is 7 Hours of Sleep Enough?

We’re used to being told that we need to get 8 hours sleep a night, but the science is far more nuanced. In this FAQ we’ll look at common sleep myths and find out why individual sleep needs outweigh arbitrary hourly targets, how brain function suffers even with almost-enough sleep, and why ‘catching up’ on weekends isn’t the answer. Spoiler: Sleep quality and consistency as much as quantity.

Is 7 hours of sleep enough?

For most adults, 7 hours is the bare minimum for physiological health – you’ll function, but you may struggle to thrive. Experts say 7–9 hours of quality sleep is the sweet spot. Consistently getting under 7 hours raises your risk of heart disease, illness and cognitive decline. If you get 7 hours, wake feeling wrecked and need caffeine to survive the day, you simply need more sleep!

What is the bare minimum sleep needed?

People with rare ‘short sleeper’ genes (DEC2 gene mutations) may be OK on 4-6 hours’ sleep a night. But for 99% of adults, consistently getting less than 7 hours nightly will leave us feeling like we’re running on empty. Chronically sub-6 hours sleep increases mortality risk by 14 – 34% and is linked to obesity, diabetes and cardiovascular damage.

Can your brain function on 7 hours of sleep?

Yes, but not optimally. Focus wavers, problem-solving creativity dips, memory recall is slower, and reduced emotional regulation will mean even the little things irritate you. Studies show reaction times slow measurably, and the accumulation of waste products in the brain can cognitive impairment, and even accelerate dementia. None of which is ideal when you need to function!

Why do doctors recommend 8 hours of sleep?

Doctors say 8 hours sleep is important because it’s a solid average required for peak performance. And it’s easy to remember! In reality some people will be fine with 7, and some will be better with 9. Most people underestimate their sleep by 30–60 minutes: listen to your body, don’t watch the clock!

There’s no benefit from having daytime naps?

Actually, a good nap can act like a system reboot. Short 10-20 minute naps boost alertness and mood, which can be particularly helpful in that post-lunch afternoon lull. Longer 60-90 minute naps can boost creativity and problem solving. But nap too long – anything over 90 minutes is inadvisable – or after 3pm, and you’ll wake groggy and potentially mess with your night time sleep.

Is 10 hours of sleep too much?

Often, yes. Regularly sleeping over 9 hours is linked to lower energy and higher health risks. Exceptions: teens, athletes, or recovering from illness. If you always need 10+ hours sleep in order to feel properly rested, consider talking to your GP about screening for sleep disorders.

Is more sleep always better?

Nope. Regularly oversleeping can leave you feeling groggy, and increase inflammation, depression and anxiety. It can also signal health issues like sleep apnoea or thyroid problems, and is linked to higher risk of stroke, heart disease, high blood pressure, and diabetes. So again, it’s a really good idea to talk to your GP if you can’t stop yourself from oversleeping.

Is 6 hours of sleep enough?

Almost never. This isn’t a willpower issue: your genetics determine whether or not you can survive 6 hours sleep unscathed. Your body doesn’t lie. If you’re not getting enough sleep:

Injuries occur more frequently and accident risk increases

Can you make up for sleep debt?

Sort of, but not perfectly. A weekend lie-in can help you feel a bit more alert after a rough week, but the debt from chronic sleep deprivation isn’t paid back so easily. It takes 4 days to make up for 1 hour of lost sleep. Catch-up sleep may reduce inflammation but can’t reverse the damage caused; your only recourse is to gradually increase your sleep to 7-9 hours and keep it there.