The entire outer layer of your skin is made up of dead cells. Exfoliating acids break them down and give way to new ones to reveal brighter, more even tone, says Ashley Hudson, senior regional manager for EQX Body Lab in New York City.
After you exercise, the surface of your face is hotter than normal, as signaled by the flushed look. That heat puts cell turnover into overdrive, she explains, making you more vulnerable to over-exfoliation. The result: irritated, blotchy patches of skin.
The bottom line:
After training, wash your face with a gentle gel cleanser like this one from La Mer. Wait to use acidic products until the post-workout redness has subsided (and ideally until nighttime), an indication that your skin temp has returned to normal, Hudson says.