Air-drying has become a core principle in the philosophy for maintaining healthy hair. For years we were taught that “no heat” drying methods are most protective and hot tools are way too damaging.
Well, contrary to popular belief, this isn’t entirely accurate…in fact, air-drying is equally as harmful as thermal drying!
Most hair strands are made up of three layers:
- Medulla – innermost layer.
- Cortex – surrounds the medulla, forms the main bulk and pigment.
- Cuticle – outermost layer; protects the hair like roof tiles, allowing water and product in between its gaps.
The moment you wet your hair, water penetrates the cuticle layer and enters the cortex.
Air-drying maximizes the amount of time the cortex can safely retain moisture. So, as it fills with water, it swells and becomes weak. The swelling and weakening will continue for as long as hair remains wet.
Hair can only absorb about thirty percent of its own weight in water, so if the cortex swells beyond capacity, it cracks the cuticle. This leads to brittle, dry, frizzy hair.
Prolonged air-drying damages hair from the inside out. The improper use of hot tools (excessive heat) damages hair from the outside in.
What to do:
After shampooing/conditioning, prep hair for styling. Be sure to include a heat protectant. Immediately begin to thermal dry (hooded/bonnet dryer or diffuse with hand-held dryer) at warm settings only, to safely remove excess moisture. Afterward, allow strands to air-dry.
Your hair will thank you.
Source: Study by Annals of Dermatology