Karen,

I do think a trainer would be a good investment for you. It's good for your cycling specific fitness, which makes your outdoor rides more fun. And it's good for your overall fitness, which makes your whole life more fun.

I find that having convenient exercise options make it's easier to keep the workouts regular. In the winter, I like to go to classes at my gym, but it's also really good to be able to just pop in a workout video & do it on my own schedule at home.