Hold up, gents: we all know sleep deprivation can reduce muscle growth – but did you know dozing too much can also inhibit progress? In this world of online fitness gurus and eight-week programs sometimes it’s hard to discern fact from fiction. Not to mention: opening Instagram and thumbing past several sets of conflicting advice (all in the same minute) can leave you more confused than enlightened.
Enter: Peter O Reilly, a fitness coach who does not sway with trends. Instead, Peter uses scientific data to guide his advice. To that end, Peter recently posted a graphic to Instagram which everyone – whether you’re an insomniac office worker, a carb-backloading gym-junkie or a layabout student – should take note of, if you want to achieve your muscle-building potential.
The ideal way to sleep for maximum fat loss and muscle gain.
While the popular belief seems to be that ‘six hours is basically fine’ and ‘anything over eight is awesome’ neither of those statements are true; if you want to achieve peak fitness, sleeping for as close to eight hours as possible appears to be your best option.
View this post on Instagram
“A study carried out in 2010 investigated the effects of sleep duration on body composition in people that maintain a moderate caloric deficit,” Peter captioned the post. “The researchers found that sleeping 8 hours per day results in more fat loss and muscle preservation when compared to sleeping only 5 hours per day.”
So far so intuitive.
Things then got interesting, when Peter pointed out that, “The research found… a significant difference between the two groups’ results as the group that slept for 8 hours lost on average 50% more fat than the group sleeping for just 5 hours.”
Not only that but, as Peter reveals, “More recent  research supports [the idea that] sleep restriction tends to negatively affect muscle preservation and fat loss while on a fat loss diet.”
“So… getting an adequate amount of sleep is more important than you think! It’s best to aim for at least 7 hours and no more than 10!”
In other words, be careful with how long you sleep, especially if you are on a low-fat diet.