Running is both your skin’s best friend (that rosy sheen) and its worst enemy (sun damage, sweat-induced acne). And need we even mention a runner’s camera-unready feet, with unsightly calluses and lurking fungi? Since you’re not going to hang up your running shoes as a skin-saving strategy, take these steps to keep your epidermis—from tender toes to the tips of your ears—safe, healthy, and well cared for.

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Running can be rough on your epidermis. Heres how to minimize the damage
A scary but not entirely surprising 2006 Archives of Dermatology study found marathoners may be at increased risk of malignant melanoma. Sure, you could run after dark or indoors to avoid frequent, unprotected sun exposure. But that’s both impractical and not much fun. Better to be consistent about applying sunscreen to vulnerable areas, says Elizabeth K. Hale, M.D., an associate professor of dermatology at New York University School of Medicine and a marathoner. “I see a lot of runners with squamous-cell carcinoma, a form of skin cancer that typically occurs on chronically exposed areas like the hands, neck, and ear tips,” she says.

Protect Yourself:
Find—and diligently use—sunscreen that works for you. (Those marathoners in the study? Only about half of them reported using sunscreen regularly.) Look for a lightweight, oil-free, broad-spectrum (blocking both UVA and UVB rays) product. A stick is good for your face, as it is less likely to drip and sting your eyes. A hat and sunglasses add extra protection, as do commonsense measures like wearing UV-blocking clothing (check labels for an Ultraviolet Protection Factor rating) and avoiding high-noon runs.

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These Runners Blisters Are Truly Nasty
Shoes & Gear blisters, calluses, and fungus. What you’re battling are the twin foot-skin enemies of moisture and friction. “Blisters pop up with what’s called fast friction,” says Gary A. Pichney, D.P.M., podiatrist at the Institute for Foot and Ankle Reconstruction at Mercy Medical Center in Baltimore. “Slow friction—rubbing in the same spot over time, builds calluses.” Meanwhile trapped moisture (e.g., between the toes) can cause what’s called maceration, in which the skin looks paler than the surrounding skin and is prone to fungal infections.

Protect Yourself:
Polypropylene or wool socks wick away moisture, and you can use plain talc or an athlete’s foot powder to prevent moisture-triggered fungus attacks. During a long run, a dab of petroleum jelly on blister-prone “hot spots” may help you prevent a pop-up. “Treat popped blisters with tincture of benzoin, available OTC, to speed healing,” says Pichney. After your run, remove socks to air your feet. Gently soften and thin calluses with a pumice; if they’re so thick that you can see a dark bruise underneath them, which could indicate a wound or infection, see your doctor or podiatrist.

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Erase Acne
Exercise increases circulation, which can keep skin clear. But for women, running so much that it interferes with your period (amenorrhea) can trigger acne, explains Dr. Hale, because the hormonal balance shifts (more of the male hormone androgen, less estrogen). And for many runners, male and female, acne happens when bacteria naturally present on the skin gets trapped in pores by sebum and sweat. Folliculitis, another form of acne, is caused by the same combo that in this case infects hair follicles, causing a crop of red bumps.

Protect Yourself:
Even though a 2008 Pediatric Dermatology study of adult male exercisers showed that showering within an hour after a sweat-drenching workout (as opposed to waiting several hours) made little difference in the existence of body acne, it still makes logical sense to keep skin clean. “If you’re unable to wash right away, use wipes, or at least change clothes,” says Dr. Hale.

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Confront Chafing
It’s your old friend friction again; skin rubbing on skin, or coming in contact with loose or ill-fitting clothing, can lead to rashes and even infection, says Dr. Hale. Chafing is most common under upper arms, beneath breasts, between thighs, or (for men) on nipples. Moisture, from sweat or a rain-soaked run, just makes it worse.

Protect Yourself:
Anti-chafing sticks or simple petroleum jelly provide a protective barrier. Be sure clothing fits snugly but doesn’t dig into your skin; is made of a wicking material; and doesn’t have irritating seams. Postchafing, use Aquaphor or petroleum jelly to protect and soothe.