Fabric: Clothes that wick sweat and allow your skin to breathe are key to staying cool. Moisture-wicking apparel pulls sweat off your body, so you stay dry and cool.
UPF: What is UPF? Ultraviolet protective factor, a rating system for sun protective apparel—almost to wearing SPF sunscreen on your skin. If you see UPF on a label, the gear has been treated with a chemical sunblock to screen out harmful UV rays. High UPF numbers indicate a greater level of protection.
Construction: During the constant, often repetitive, motions of a workout, clothes can rub your skin raw. Avoid this by choosing clothes that are made to reduce chaffing. Check the seams!
Color: In the summer, the color of your clothes matters. Wearing white or very light colors keeps you cooler, because they refl ect sunlight better than black or other dark colors. However, light colors will not protect you from sunburn as well as dark colors, because they do not deflect UV rays as effectively. The best bet: choose a happy medium, a bold green or bright blue, which provides better sun protection than white or other light colors, but keeps you cooler than black or other dark colors.