Ironman?

My son has been trying to talk me into doing an Ironman for a couple of years now. I've finally decided that I will start getting ready to do it. I know I can bike the 112 miles, I may be able to swim 2.4 miles, but I know right now I could not run 26.2 miles.

So today after doing my normal hour Spinning I went for a jog down the road and back. I know it isn't far or fast but I need to get my legs use to running instead of just biking. I think I will continue with short jogs like this for this week and then up the distance next week.