Good Exercises for the Horse Rider?

I know I'm not the only one who can't come out to the barn every day to ride, and it can affect how fit you are to ride. For me, I get aches and pains in my legs and abdomen if I ride for very long. It inhibits my riding and I can't use my body as much as I need to.

So, what are some good exercises to keep a rider fit for riding when they're off the horse?

Make sure you stretch when you get in the saddle to, but here is some helpful websites here-
Exercise for Horseback Riding - Horse Riding Fitness
Groundwork for the Rider Exercises
How to Get Into Shape for Horseback Riding

I ride every day, but I still need to keep fitter for the level I am doing. I find that doing cardio, full body strength and core work are what help me the most.
Right now my routine per week is 50 minutes of spin (indoor cycling), 30 minutes of regular yoga or stretching, 60 minutes of active hot yoga, 60 minutes of circuit training with cardio, weights (upper and lower body) and ab work on top of riding 1 horse every day. During the summer I cycle every day and during winter I'm going to start cross country skiing as well once or twice a week. I like being fit if you can't tell!! I believe that maintaining a high level of fitness is the number one way to improve your riding and prevent injury!