I'm in my late twenties having -6D spherical rx.
Since I started running regularly for about 2 years (not sprinting, more like jogging) I noticed new floaters. Went to see a doctor, no issues at all.
I'm running on the same track that is made of a rubber-ish material and wearing running shoes whose feet are thick and soft.
Still, do you think the pounding due to running caused these floaters?