The issue is unless the guy has an equal amount of passion and drive (It doesn't have to be for triathlons or training, just for SOMETHING) he will feel insecure, and like he is a moth to your flame, and will be consumed by you.
For most men, this is a complete turnoff and will leave them to subconciously reject you, and they will give themselves justifications why, as they wouldn't want to realize the truth.
That leaves you with either a submissive man, who would be happy to be your moth (From what I have gathered, this is not something you would enjoy, or would it?) or a man with equal drive/confidence in himself to see you enjoying what you love, and enjoy what he loves as well.
This is also something that tempers with age and experience, so you'll see a lot more kindred spirits as you get older. Take heart gorgeous
