Endurance Athletes at high risk for skin cancer and melanoma.

Fall is marathon season! Whether you’re running in Death Valley (December 4), or Honolulu (December 12), you share certain habits: You support your feet with well-fitting sneakers. You keep hydrated. Maybe you wear knee braces or wrap your ankles. But do you protect your skin from the sun’s ultraviolet (UV) radiation? You should, because exposure to UV radiation increases your risk of skin cancers, eye diseases, and some immune-related disorders.

Participants in outdoor sports face a higher risk of nonmelanoma skin cancers, like basal and squamous cell carcinoma, the two most common skin cancers.

Outdoor endurance athletes – like marathoners – also show more signs of risk factors for melanoma, such as numerous small moles or any large, atypical moles. Outdoor endurance athletes’ higher risk of melanoma may be related to the sun damage they sustain from excessive UV exposure. Additionally, marathoners tend to have depressed immune systems, due to the amount of UV exposure they receive and the extremely intensive training they engage in. According to a study in Sports Medicine, UV-induced immune system suppression may promote the development of skin cancers. Melanoma is the deadliest form of skin cancer, and will cause an estimated 9,000 deaths this year in the US alone.

But … it is possible to protect your skin while you’re running? Here’s how:

Problem: You train outdoors, and that means many hours of exposure to the sun’s harmful ultraviolet (UV) radiation.

Sun-Safe Solution: Since the sun is strongest between 10 AM and 4 PM, train in the early morning, late afternoon, or evening. This way, you’ll reduce your exposure levels while maintaining your mileage. Plus, the generally lower temperatures around dawn and dusk will make exercise more comfortable.

Problem: The tank tops and shorts you train in leave a lot of skin exposed.

Sun-safe Solution: “Protective clothing is the most important first step,” says dermatologist Elizabeth K. Hale, MD, who has completed the New York City Marathon three times. Specially formulated, breathable fabrics (such as microfibers) wick away sweat, so that you can stay cool, even when wearing clothes that offer more protection, such as long sleeves, leggings, or pants. Wear dark or bright colors, since they absorb more UV than do whites or pastels

You may want to look for athletic gear with an ultraviolet protection (UPF) label; this indicates how much of the sun’s UV radiation will be absorbed by the fabric. For instance, a shirt with a UPF of 30 will allow just 1/30th of the sun’s UV radiation to reach your skin. The Skin Cancer Foundation recommends clothes with a UPF of 30+. Laundry additives can also wash UV protection into your clothes for up to 20 washes.

Hats – one with a 3″-brim is best – and sunglasses (look for a pair that blocks 99-100 percent of the sun’s UV rays) are just as important, and we have tips on choosing the right ones.

Problem: You apply sunscreen, but you seem to sweat it off almost immediately.

ssn_25_3_bottle127x158Sun-safe Solution: Look for water- and sweat-resistant lotions, gels, sticks, or spray-on sunscreens, versions of which should be available at your local drugstore. Sunscreens with “sport” or “active” in the name are usually designed not to rub off or to sting if they get into your eyes. The Skin Cancer Foundation recommends that everyone wear a sunscreen with a sun protection factor (SPF) of at least 15; runners may want to up the SPF to 30+. The sun emits two kinds of UV: UVA (long-wave), and UVB (shortwave) rays. SPF numbers indicate protection against UVB, but since UVA can reach the skin, too, “It’s important to pick a sunscreen that offers both UVA and UVB protection,” says Hale. So choose a sunscreen with some combination of these UVA-blocking ingredients: avobenzone, ecamsule, oxybenzone, titanium dioxide, and zinc oxide.

For long-wearing sun protection, mineral or inorganic sunscreen ingredients like titanium dioxide and zinc oxide may be a good choice: “Zinc oxide tends to stay on better despite sweat or rubbing,” says dermatologist Amy Amonette Huber, MD, a long-time athlete. “I use zinc oxide on my face – SPF 60 – and then I use an SPF 30 or 50 spray formula on other exposed areas. It’s convenient and less messy to put on.”

It’s important to apply a full ounce (two tablespoons) of sunscreen to the body, including a nickel-sized dollop to the face. And be sure to apply your sunscreen 30 minutes prior to heading outside, not just before you start running. That way, your skin will have time to absorb the sunscreen. It’s necessary to reapply sunscreen after two hours outdoors, or more frequently if you’re sweating heavily. Luckily, if you carry several lightweight, one-use, sunscreen wipes in your pocket, you can stay protected without breaking your stride.

So suit up, and stay sun-smart. If you follow these tips, you may experience some soreness after the event, but your pain will come from a race well-run, not a skin-damaging sunburn.