Athletes involved in outdoor sports, even winter ones, may be at higher-than-average risk of skin cancer, according to a research review.

The more time athletes spend training and competing outdoors, the greater their risk of developing skin cancer, researchers report in the summer issue of the journal Sports Health.

That means that summer sports carry the greatest risk, partly because athletes often train in shorts and sleeveless shirts that leave much of their skin exposed.

But even athletes in winter sports are vulnerable, according to Dr.

Wilma F. Bergfeld and Shannon C. Harrison of the Cleveland Clinic Foundation.

Skiers and snowboarders, for instance, spend much of their time at high altitudes, with the sun reflecting off the snow and onto any exposed skin. One study of skiers at an elevation of 11,000 feet found that athletes’ unprotected skin started to burn after only 6 minutes of UV exposure.

Other studies have found marathon runners, mountain climbers and surfers to have higher than average risks of skin cancer compared with other types of athletes.

The bottom line, according to Bergfeld and Harrison, is that all outdoor athletes should take measures to protect their skin from the sun’s rays. Ideally, the researchers write, athletes should avoid training when UV radiation is highest - between 10 a.m. and 3 p.m.

Beyond that, they should use sunscreen, wear hats and cover as much skin as possible, and don sunglasses when practical.

Summer athletes may find it hard to cover up because of the heat. However, Bergfeld and Harrison point out, there are newer clothing lines with built-in UV protection and light, breathable fabrics that may make long sleeves more feasible for summer athletes.

Sunscreens, they note, should be “applied generously” and reapplied every 2 to 4 hours, or after an athlete starts sweating or gets wet.

Athletes are not the only ones at risk, however. Coaches and trainers who spend long hour outdoors should take the same measures to protect their skin, the researchers advise.

SOURCE: Sports Health, July/August 2009.