I see folks from the Atlanta Track Club about once a week over on the "track", about half are ladies about 20 or so. They are in good shape.
I will be slogging alone and hear the group of 5 or so guys coming up behind me and get out of their way. I sort of remember being able to run like that, or close to it. They are fast.
I saw some dude recently broke the 400 m indoor record, 44 seconds and change. Obviously that's four 11 second hundreds, which is pretty fast, back to back to back to back.