I got my fiance into running. We have been together 6 years, and always ran together until this year. The only downsides I found with it was that I was always holding back a bit to go at her pace, and she never wanted to do interval type stuff.... but that's a small price to pay to have a mutual past time you can share, and I did not miss out, as I have never been interested in racing.
Last year she had a bad accident skiing and after a week in hospital, she has titanium holding the tendons in her knee together. Now she goes to the gym and physio sessions instead. She does love running but the knee is not up to much, so she does a 45m jog in the park once a week, I go with her and do some intervals.