After races or hard training days, Bontrager's RXL Recovery Compression Socks help your legs recover more quickly. Profila Power yarns provide graduated compression from your feet to above your calves for optimal circulation, oxygen flow and recovery. The fit is based on the girth of your calves, so you're sure to get a perfect fit. Although these are called "recovery" socks, we love these socks DURING rides as well, the compression really supports the muscles and helps with endurance. We also swear by them for air travel, too.