I'm 4.5 weeks post and walk 3.25 miles (almost) every night. The first time I tried walking, for exercise that is, was 2 weeks post. I made it a mile and realized it was catching up to me fast. I turned around and about 1/2 way home didn't think I was going to make it ...things were cramping, my stomach hurt, I had zero energy all of the sudden, etc. Needless to say, I eased back into from there.