I have started running 1 mile a day. My total walking has increased to 6-8 miles a day from 4-5. I hate running and I find that a 1 mile limit gives me incentive to run fast and push myself without making me quit. The first day it took me 13 minutes. Now I run around a ~9:30 mile. I think I will continue doing it. Its dropped my resting heart rate from 55bpm to 48bpm.