Don't know if it's just a mental thing but I seem to have more seperation in my quads since I've been riding to work for the last 5 months or so. And it's only a short ride, 5mins each way so I always make sure I sprint it. Usually huffing and puffing and can't walk properly for the first minute or so.
Doing regular PTC beginners program squats. (except for a few months ago when I was injured)