In the busy world we're living in, we're always looking for ways to save time when it comes to our beauty routines. That's why you'll often catch us face masking while binging our latest TV show obsession on Netflix or leaving on a skin-care mask overnight so it can work its magic while we catch some Z's.

But as much as we love maximising our time, there are a few beauty activities that shouldn't be combined, like using a hair mask [1] and sleeping. Now, you may be thinking to yourself, "I've never thought of sleeping in a hair mask before," but according to a few top hairstylists, it's actually more common than you might think.

While it may seem harmless to put in a hair mask before going to bed to really allow the ingredients of the treatment [2] to sink in while your sleep, that can actually cause more harm to your hair. Like other beauty treatments, there is such a thing as too much of a good thing.

"Even though our hair is 'dead,' it's still important to allow our hair to take in oxygen," celebrity hairstylist Jonathan Colombini [3] told POPSUGAR. "If you wear a mask overnight, you're creating a barrier over the cuticle, not allowing hair to breathe. Also, some masks have a high level of protein in them, and over-protein use will lead to breakage."

You don't have to be sleeping to leave a hair mask on for too long. Applying a mask and leaving it on while you go about your day can lead to the same breakage. To ensure you're not overdoing it, Colombini recommended you read the directions but added, "in my experience, most hair masks stop becoming beneficial after 20 minutes of application." Simply use a mask, like the L'Oréal Paris Elvive Total Repair 5 Power Restore Multi-Use Hair Treatment [4] ($13), the R+Co On a Cloud Baobab Oil Repair Masque [5] ($44), or the Anomaly Deep Conditioning Treatment Mask [6] ($7), in place of your conditioner in the shower to reap all of the benefits you could need.