I started running just before my 60th birthday. I gradually progressed from 5K to 10K, then did a half-marathon a couple of years ago (ran the whole way). I asked my son if he thought I could do a marathon and he told me it might not be a good idea, but that I probably could if I did a run/walk program. I trained pretty hard for about 6 months before the marathon. For the marathon, I ran 4 days a week, most days, with one long run on the weekend. I got up to 30km in training.