ok im 6'1 185 and im a male. I used to be a heavy smoker, so im worried about my stamina. I dont smoke now but im still concerned. Im in ok shape, (can walk for hours on end) but cant seem to jog very long. Im wondering if i stay under 2000 calories a day (which is pretty eazy since im not a heavy eater) and walk 5 miles every other day (actually 4.7) and jog 2 miles on the days in between. (actually not joggin the whole way, but most of it and little walk breaks because i just cant keep going. would this be enough to get in better shape or do i need to do alot more?