I also do a lot of athletics in the sun--cycling, but also climbing and ski touring--where sweat wicking fabric and breathable clothing is crucial. Over the years I've acquired several sun protective hooded long sleeve shirts which don't cause me to overheat. I've got a helmet, sunglasses, and short or pants on, as well, so I end up putting sunscreen on the few parts of my body which are exposed. Bottom half of my face, back of my neck, and bottom half of my legs.