Sunscreen season is here. But most people with desk jobs have to worry about slathering up only if they go to the beach or the pool on weekends.

But what about those who need to be outside to do their jobs or, for that matter, favorite activity?

Swimmers, runners, golfers, tennis players and other athletes often train and compete during the most sun-damaging hours of the day, 10 a.m. to 4 p.m.

“If you’re going for a run midday in the summer, wear a hat, protective clothing and sunscreen,” says Summer Sanders, a 1992 Olympic champion swimmer who has had three melanomas removed. “I never associated skin cancer with training. But the truth is, there is risk associated with any prolonged exposure to the sun.”

But let’s face it: If you’re going for a midday run in summer, it’s going to be hot, and you might not want to wear a hat or long sleeves. Plus, sunscreen might make you feel as if your pores are clogged and you can’t sweat — essential for cooling down.

That’s how Patrick Serfass, a District resident and triathlete, says he feels about sunscreen. He’ll wear it reluctantly while training but says that in the end, it affects his performance. So on race day, he goes sunscreen-free (and deodorant-free) to sweat more and cool better.

“My body can sweat more easily, which means I cool faster, and that’s key for performance,” he says.

Why even bother to run (or play tennis or golf) during peak sun hours? Can’t you just train in the early morning or late at night?

Not if you need to make sure your body can handle the conditions under which you’ll be competing, Serfass says.

Failing to do so “can kill your race,” he says. “You have to get your body used to the heat and humidity.”

Some athletes in the Washington area consider summer workouts their version of altitude training. In other words, if you train in these horrid conditions and then compete under milder conditions, your results could be better than expected.

Before moving on to other sun-blocking options, let’s take a moment to look around the sunscreen aisle: What type? How much? When to apply?

“You want an SPF 30 or more, broad spectrum and water-resistant sunscreen,” says J. Leonard Lichtenfeld, deputy chief medical officer at the American Cancer Society, referring to the sun protection factor, which measures how well sunscreen protects your skin. “And follow the directions. Reapply when it says to reapply, and use generous amounts.”

Remember that there is no such thing as building a base tan. A tan — any tan — is a sign that skin is unhealthy, Lichtenfeld says.

“It’s the skin’s way of saying, ‘I have a problem,’ ” he says.

Marty Braun, a District-based dermatologist and Mohs (skin cancer procedure) surgeon, says he recommends a daily lotion or face cream that includes SPF, even if it’s as low as 15. (This is for you, office workers whose exposure is limited to commuting to and from work.)

For prolonged outdoor activity, he recommends SPF 30 or higher. If you want to be completely covered, use sunscreens that have physical, as opposed to just chemical, blockers, such as zinc and titanium.

But Braun also understands athletes’ resistance toward blocked pores and having to reapply mid-match or mid-race.

“You’re damned if you do, and you’re damned if you don’t,” he says. Like Serfass, he recommends wearing sunscreen when you train and going without it only when you compete. It isn’t a perfect solution, but it’s something.

Another way to shield yourself from damaging rays is to wear protective clothing, such as broad-brimmed hats and long-sleeved shirts — though it’s hard to imagine any athlete wearing a broad-brimmed hat.

“I don’t think we’ll convince tennis players to wear sombreros when they play,” Braun says.

No, but maybe a hat that shades the face and head. Then you could apply sunscreen to the back of your neck and ears, common areas for skin cancers.

There are also lightweight, long-sleeved workout shirts available, such as those by the brand Coolibar (coolibar.com), that are sun-protective.

To stay cool while wearing sun-protective clothing, Serfass says, carry two bottles of water on long training runs and rides — one to spray yourself with and another to hydrate. (He adds electrolytes to that one.) And if he’s wearing a hat, he’ll fill it with ice when it’s really scorching.

Serfass, who surfs, has found that the sunscreen brand Headhunter (headhuntersurf-com.myshopify.com) protects him when he’s catching a wave.

Kids need to be careful, too. Sanders, who promotes skin cancer education for young lifeguards and swimmers through the group Block the Blaze, says she hopes parents and coaches will help their kids stay clear of this statistic: About 4 million Americans are diagnosed with skin cancer every year.

“I have dark skin, dark eyes, dark hair, and I never thought it would happen to me,” she says.

Remember, she says, a tan body is not a sign of health.

“We need a cultural shift,” she says, adding that she can’t believe the tanning bed fad is back. “Knowledge is power, and we now know that skin cancer can happen to anyone.”

Boston is a fitness trainer and freelance writer. She can be found at gabriellaboston.com.