The Active Girl's Guide to Beauty

WORKOUT WOE
An Oily or Dry Scalp
Workouts can make your scalp go to extremes: Sweat can trigger oiliness, while frequent post-exercise cleansing can cause dryness.

Treat It
Both conditions can be avoided if you use a dry shampoo after working out, says Toye. "It's the perfect post-workout cleanser because it sops up oil. And since you brush it out, it won't aggravate a dry scalp like a daily shampoo might." We like Klorane Gentle Dry Shampoo ($18; sephora.com), with oat extract.

Prevent It Don't use the shampoo in the gym shower. "Even at upscale facilities, it's pretty harsh, since it's meant to deep clean sweaty heads," Toye says. So bring your own mild formula instead. Colbert recommends Neutrogena Clean Replenishing Moisturizing Shampoo ($5; at drugstores), which is formulated for frequent use. If you exercise every day and tend toward dryness, work the lather from your ends to your scalp, leaving a buffer zone of half an inch from your part, where oil is produced. To keep greasiness in check, massage shampoo into your scalp at your roots and let it sit for 60 seconds.