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].