Dear Rosy: Lucy applauds your commitment to good health and exercise! For an answer to your question, she turned to MIT Medical dermatologist Allison Larson, who hastened to calm your fears. “Turning red after (or during) exercise is normal and common,” Larson assures Lucy.
Sweating is one way the body cools itself, Larson continues. “Another way is by dilating—or expanding—the small blood vessels of the skin.” On the face, she explains, these blood vessels are very close to the surface, and when they are dilated, the face appears red. How flushed one appears after exercise is highly individual, however. “These blood vessels tend to be more obvious in light-skinned people,” Larson says, “and some people’s blood vessels dilate more easily and stay dilated for a longer time.”
Lucy hopes this explanation has put your fears to rest. She encourages you to continue working up a sweat—and a blush—and to wear that post-run red face as a badge of honor. —Lucy