Air-dry vs blow dry – which is really worse for your hair?

With the arrival of the air-dry (a fancy name for letting hair dry naturally at room temperature), our hairdryer has, frankly, started to see less and less action. After all, experts have warned us for years about the effects of prolonged heat damage including split ends and dry, brittle strands that break off. As you might imagine, it makes sense if you assault your hair with temperatures so high, steam wafts off the strands. But according to hairstylist Cim Mahony, who has worked with everyone from supermodel Kate Moss to HRH Crown Princess Mary of Denmark, the argument that air-drying is a healthier option for your hair, is actually a myth.

“Gently blow drying with the right hairdryer on the lowest heat and speed setting until it is 90 percent dry, is actually better for the hair than air-drying,” says Mahony, adding that this largely comes down to your hair’s response to being wet.

It’s thought that hair can astonishingly absorb up to 30 per cent of its own weight in water. This, in turn, causes it to swell and become weak, while also putting pressure on the bonds that hold the hair together.

“A strand of hair consists of several different bonds, including hydrogen bonds that are broken when hair gets wet,” says Mahony, which is the reason hair can be restyled into a different shape from wet to dry. “When hair is wet it is stretched out, the result of water putting all these bonds under pressure, even the stronger keratin bonds. Hair also loses its elasticity when wet, which means it will be more prone to breakage or being ripped out at the root. This is why you should never have wet hair for longer than necessary.”

A study at Yonsei University in Korea, which compared air-drying with heat drying, corroborates this. Researchers found the hair’s cell membrane (the material that ‘glues’ hair cells together) was only damaged in the naturally dried group, as a result of staying in contact with water for longer. They also found that using the right technique when blow drying is better for the health of your hair.

Here Mahony reveals his fool-proof way to prep and blow dry hair, no damage necessary:

Step 1: Before showering, use a Mason Pearson boar bristle brush to evenly distribute oil through your hair.

Step 2: Shampoo and then condition, using a wide tooth comb to gently distribute product and detangle.

Step 3: Towel dry hair, preferably with a microfibre towel such as Aquis Lisse Luxe Hair Turban.

Step 4: Use a hairdryer on a low setting and move it in a constant motion around the head. I’m a big fan of using the Gentle Air Attachment on the Dyson Supersonic hairdryer as the gentle airflow doesn’t disturb the cuticle while drying, making it safer for your hair. Avoid using a brush or any other tools while blow drying.

Step 5: Apply leave-in conditioner when the hair is roughly 80 per cent dry. This will ensure that your strands can absorb it without putting the bonds under unnecessary strain.

Step 6: Hair regains strength and elasticity when 90 to 95 per cent dry. At this point, you can use a round brush to lock in the hydrogen bonds and create a new shape and style.