Although eight hours of sleep is often recommended as the ideal, not everyone needs that amount.

Have you noticed that you struggle to open your eyes after 6 hours of sleep, while your partner might be bouncing out of bed bright eyed and bushy tailed with the same amount, or even vice versa?

New research shows that when it comes to how much sleep your body actually needs, it depends on your DNA.

Researchers have found that sleep preferences can be partly genetic and sleep traits are often hereditary and some people with specific genotypes require different patterns of shut-eye.

“It is well-known that the circadian clock regulates sleep, and thus, one might expect clock mutants to exhibit sleep phenotypes. On the other hand, circadian and homeostatic controls may be, at least partially, independent systems, and thus, mutants could be specific for one system or the other,” states author of the study Amita Seghal.

“For instance, the sss mutants have normal clock function. Similarly, circadian clock mutants may disrupt the consolidation of sleep (so that it does not occur in a major block of time at night), but they need not alter the total amount of sleep, which is a measure of homeostatic regulation,” she adds.

In particular the study cites that certain genotypes require a different sleep architecture to others.

“Individuals with autosomal dominant trait have normal sleep architecture, and a lifelong tendency to wake and sleep at very early times (i.e., 1:00 a.m.– 3:00 a.m. and 6:00–8:00 p.m., respectively),” Anita writes.

“Melatonin and temperature rhythms are advanced by 4–6 hours, and the free running period (i.e., the period of rhythms observed in organisms in the absence of any environment clues, thereby indicating endogenous clock time) has been measured as 1 hour shorter than in controls. Underlying mutations in two pedigree populations point to defects in phosphorylation of PER2 as the core issue, with mutations identified in both PER2 and Casein Kinase 1 genes (CK1δ),” she adds.

So, what does this mean for you and how do you find out how much sleep you need? Not everyone has the option to get their genes tested, so playing around with your alarm clock might be one way to work out which option works for you.

First of all, see how you feel after 8 hours of sleep. If you find yourself waking up groggy, then perhaps you need less sleep. Set your alarm clock to wake up half an hour earlier and test yourself on 7.5 hours of sleep.

If you still feel sluggish then try reducing the amounts by half an hour until you find your magic number.

If you struggle to find your magic number still then speak to your local professional about a DNA test and which sleep cycle best works for your body.