But it is repairable. I quit smoking in February and now see or show no signs of it. I can run farther and work out harder than I ever could before starting. My lung capacity is just as good now also. In order to increase your oxygen delivery system, try doing some tabata style running and working out. It is where you work out full blast for 20 seconds (no pacing) then stop and rest 10 seconds. Do that with a few different exercises for 4 minutes each. I will greatly increase your limits fast. You can find all kinds of info about it online. Wikipedia has a good article for it and HIIT (high intensity interval training). Good luck!

If you register for one now, that’s say 6 to 8 months out—it can be quite inspiring. It takes the whole “I’m going to run a marathon” thing, from a theory to a “I’ve committed money”, sort of reality.

The actual training aint so bad. I think you’ll find that most training guides have you jogging like 5 miles a couple of times a week, with a long run on weekends.