User blog comment:Rassilon of Old/Silhouetted characters on the Young Justice: Invasion poster revealed!/@comment-3118271-20120502173702/@comment-5046348-20120502210734

Given that Jay Garrick looks in a remarkably good state for a bloke in his 90s could imply it I suppose but one would assume that speedsters have longevity rather than slow aging. All that running has to keep you fit. :P