Walking within a week. Speed walking with the baby jogger by 3-4 weeks. Didn't start to run until cleared by midwife at 6 weeks (it was a bit of a tough vaginal delivery.) Running 5K races by 8-9 weeks.
My doctor had me started walking the day after delivery. I slowly added different exercises each week. I was running 5ks again by 6.5 weeks postpartum.
Re: How long did you wait to exercise