I did a few 4 hour marathons in my early 20s, and in December I decided I was going to train for another one, after doing very little cardio for a long time. Th

I did a few 4 hour marathons in my early 20s, and in December I decided I was going to train for another one, after doing very little cardio for a long time. The run/walk approach has been great for me. I run for as long as I can, then walk 100m, run 400m… until I think I’m done. I’m getting through 10k in just over an hour now, and when I started I was struggling to mostly walk 5k.