While they don't have to be by your side sweating it out on the treadmill, it does help to have someone who will support and encourage you to get out the door. So, sit them down and explain to them exactly what your goals are and what you need from them. Whatever they are, be specific so they don't have to guess. (Maybe it's more help with the kids while you work out or simply checking in with you as far as whether you reached your workout goals for the week.)
I'm lucky that my husband loves to work out and sees the importance in staying fit. We both talked about our goals for 2012 and are on board to help each other reach those.
Just yesterday morning, my husband had gotten up early to work out and thought it would be fun to go to brunch for his last day off of work. I still needed to workout and had planned to go on a run in the morning shortly after he returned and could watch the kids. While I wanted to go to brunch and enjoy myself, in the back of my mind I knew if I didn't workout in the morning, it probably wasn't going to happen. The guilty mother in me said, "I'll just workout later, let's go to brunch." I think my husband knew I was going to feel guilty so he said, "Why don't you just run downtown and meet us there." Brilliant. Why didn't I think of that.
Nothing wrong with having brunch in your stinky running clothes. So, I did just that, got in a 45 minute run on a different route, had brunch with my family and ate guilt free. :)