Answer: An ionic dryer emits negatively charged ions that boost hair health. The negative ions break down water molecules to one-fifth of their size, so they're able to penetrate each shaft, hydrating from the inside out. This makes the cuticle lie flat, encouraging glossy shine, says Michel Obadia, head stylist of the Pierre Michel Salon in New York City. Try: Remington SuperSonic 1875-Watt Ionic Hair Dryer, $30, at drugstores.
Originally published in Fitness magazine.