As an outdoor athlete, you should look for a broad-spectrum sunscreen with an SPF of 30 or higher to protect against both UVA and UVB rays. Choose a formula labeled 'water-resistant' (effective for up to 80 minutes) so it won't easily wash off with sweat. Mineral sunscreens containing zinc oxide or titanium dioxide are excellent choices as they are highly effective and won't sting your eyes when you sweat. Reapply every two hours, or immediately after towel drying. Additionally, protect your skin by wearing UPF clothing, a wide-brimmed hat, UV-blocking sunglasses, and an SPF lip balm. Enjoy your training safely!