I am in my mid 40's and had knee surgery last year. My running has been a struggle in terms of trying to get back into decent competitive shape. I was a 1:14 half marathoner in my prime and my marathon pr is 2:41. I find it hard to train hard only to know I will never reach those times again.So I am thinking of doing a 1/2 Ironman in the fall and posssibly a full Ironman next year. I would like to hear from those who were runners who turned triathlete. Do you get the same challenge and motivation that you did when you were just a runner? How do you enjoy doing ironmans?