The Strange Reason Your Skin Itches When You Work Out

Breaking a sweat might spark a surprising urge—the one to itch.

Itchy skin is actually a pretty common response to exercise, says Michael J. Ryan, Ph.D., associate professor of exercise science at Fairmont State University.

Related: THE 21-DAY METASHRED: a Body-Shredding Exercise and Diet Plan From the Men’s Health Fitness Director

When you get moving, your heart pumps more blood to your working muscles, like your thighs while running, or your chest while bench pressing. This fills millions of capillaries.

“As the capillaries expand, they push outward, stimulating surrounding nerve cells, which in turn sends signals back to your brain,” explains Ryan. 

The result? Your brain translates these signals as an itch.

The only thing you can do to lessen the itch is to maintain a workout routine. If you exercise regularly, your brain gets accustomed to the signals and starts to ignore them.

Related: Why Scratching an Itch Only Makes It Worse

But the longer the break you take from the gym, the more intense the itch will be when you return, says Ryan.

If your itching comes with welts, hives, or a feeling of faintness, call your doctor. This could be a more serious case called exercise-induced urticaria.

(Check out 7 Other Bizarre Side Effects That Happen to Your Body During Exercise.)

Cassie ShortsleeveFreelance Writer

Cassie Shortsleeve is a skilled freelance journalist with more than a decade of experience reporting for some of the nation's largest print and digital publications, including Women's Health, Parents, What to Expect, The Washington Post, and others. She is also the founder of the digital motherhood support platform Dear Sunday Motherhood and a co-founder of the newsletter Two Truths Motherhood and the maternal rights non-profit Chamber of Mothers. She is a mom to three daughters and lives in the Boston suburbs.