There is no data on this but ...... I've treated runners for many years, have many friends and family who run (including marathoners) and run myself 2-3 times a week.  As long as runners sunscreen with a good sunscreen (consider even double layering), and wear a hat,  most have good skin!  It's the sun damage that causes the sagging which is the result of the destruction of collagen and elastic fibers by the ultraviolet rays.   In competitive runners who get down to the very low body fat range, the fat pads of the face may temporarily shrink causing the outer layer to sag a little.  Gaining a little weight corrects this.  Info on how to layer sunscreens for outdoor sports.     Dr. I