Top 5 Sunscreens for Athletes

Sun protection factor (SPF) is the key component of an effective sunscreen. SPF refers to the amount of protection the sunscreen will give you, or how much longer you can spend outdoors before you get sunburned compared to if you weren't wearing sunscreen.

Here's how SPF works:

Say you normally can stay outside in the sun for 20 minutes without burning. If you slather on an SPF 15 sunscreen, you can stay outside for 15 times longer -- about five hours -- before burning. The higher the SPF, the greater the protection the sunscreen provides. An SPF 15 sunscreen blocks 93 percent of UVB rays, an SPF 30 blocks 97 percent, and an SPF 50 blocks 98 percent. The SPF of a sunscreen only relates to UVB rays -- there currently is no rating system for UVA protection, but it's in the works.

It would seem logical that an SPF 30 sunscreen would be twice as effective as an SPF 15 sunscreen, and an SPF 100 would be six times more effective, but that's not really how it works. Although a higher SPF sunscreen will protect you slightly better, the numbers game in sunscreens is mostly marketing (in fact, the Food and Drug Administration has proposed capping the SPF at 50+). Dermatologists say you're fine using an SPF 30 or SPF 45, but just make sure to reapply the sunscreen every two hours or so [source: WebMD]. If your skin is starting to take on a reddish tinge, reapply sooner.

The best sunscreens protect against both ultraviolet A (UVA) and ultraviolet B (UVB) rays. UVA rays penetrate more deeply into the dermis -- the deepest layer of your skin. These rays not only can age your skin prematurely, but they can make it more difficult for your immune system to protect you from cancer. UVB rays don't penetrate as deeply but they are what cause your skin to burn. Both UVA and UVB rays contribute to premature aging, freckles, age spots and wrinkles. Too much exposure to both of these types of ultraviolet rays can increase your skin cancer risk.

When choosing a sunscreen, look for labels that indicate that the brand has broad-spectrum (UVA and UVB) coverage, and look for a combination of these ingredients:

Block UVA rays:

Block UVB rays:

Block both UVA and UVB rays:

The last thing you want in the middle of a big game is to have your sunscreen drip into your eyes. (If you've ever had sunscreen in your eyes, you know how much it burns.) Look for a sunscreen that's labeled "water-resistant" or "sweat-resistant," like Coppertone Sport Ultra Sweatproof, Hawaiian Tropic Ozone Sport Sunblock, or Banana Boat UltraMist Sport Performance Continuous Spray. A water-resistant sunscreen will maintain its SPF for as long as 40 minutes underwater (unless you rub it off).

Even though you may still see sunscreens labeled "waterproof," there really isn't any such thing. No sunscreen can be entirely waterproof, because all of them will eventually wear off if you submerge your body in water for long enough. Water-resistant is the more accurate label. No matter how water- or sweat-resistant your sunscreen is, you'll need to reapply it about every two hours, and sooner if you're sweating a lot [source: Skin Cancer Foundation].

Why waste your time comparing brands in the aisle of your local drugstore, when a few reputable organizations have already done the work for you? Look for sunscreen brands that carry these seals of approval:

The Skin Cancer Foundation Seal of Recommendation: This seal is given to products that help prevent "sun-induced damage to the skin" [source: Skin Cancer Foundation].

Sport sunscreens that get the Skin Cancer Foundation's approval include:

For a full list, visit the Skin Cancer Foundation's list of recommendations.

The American Academy of Dermatology has its own SEAL OF RECOGNITION that it grants to dermatologist-approved sunscreens with proven sun-protection benefits. These sunscreens include:

For a full list, visit of the American Academy of Dermatology's list of recommendations.

Sunscreens come in different varieties: lotions, creams, sticks and sprays. Choose the one that's easiest for you to apply, especially one that's easy to reapply when you're in the middle of a game on the field, court or green. Sometimes a spray may seem easiest, but if it's windy outside you may find that more sunscreen blows away than ends up on your body.

Don't forget the accessories, like sunscreen lip balm to protect your sensitive lips. ChapStick Ultra SPF 30 and Hawaiian Tropic Aloe Vera Sunscreen Lip Balm 45+ are both options. Also consider using a sunscreen for your scalp (especially if you're thinning a bit on top).

Make sure the bottle you choose contains enough sunscreen to last you all day. You need to apply at least 1 ounce to get the full protection, and reapply it at least every two hours, especially if you're sweating a lot or toweling off. During a long outdoor game, expect to use up to half of an 8-ounce bottle of sunscreen. Studies show that most people use only half of the sunscreen they need [source: Skin Cancer Foundation]. When you skimp on the sunscreen, you exponentially decrease your sun protection. For example, applying half an ounce of SPF 70 sunscreen instead of the full ounce will give you an SPF of just 8.4 [source: Saint Louis].