Buy a bike, not only works your legs and lungs but saves you gas money! Also, if you have a hill near you, fun to go down. Or get a bike machine for
indoors.
there that basiclally sums it all up.. do like 3x10 with each with like 10 sec breaks in between. do it for like 12 weeks eat right, get enough rest
and you will see major leg improvment.
but for sprints just to like 10 intervals with 10-20 sec rest but dont stop keep walking.