A: I've always thought one of the best things about exercising—maybe the best thing—is taking a shower afterward, and I love the feeling of squeaky-clean hair. If you exercise regularly, and your hair is dry (as mine is), you could just rinse, or use a shampoo labeled "gentle," "lightweight," or "daily," says Nick Arrojo, owner of Arrojo Studio in New York City. Apply a small amount (about the size of a nickel), don't overmassage, and be sure to rinse thoroughly. Also, before you shampoo, you could apply a little moisturizing conditioner on your wet hair, from midpoint to the ends; then shampoo starting with the roots and work down. The conditioner will diminish the drying effect of the shampoo, says Kevin Mancuso, creative director for Nexxus.
Bottom line: Just rinsing after workouts is usually fine, but use a moisturizing shampoo and conditioner once or twice a week.