Can you get too much of a good thing?

Since Trikking is really a whole body exercise, I find myself asking the question "can I do it too much?" When I was Trikking today I was focusing on what muscles or muscle-groups I'm working when I Trikke. I feel I work the triceps, shoulder, chest and back muscles more than the biceps. I have found muscles in my forearms that I didn't know I had. I feel it works all the leg muscles. Then, when I get it just right and get the upper and lower body working together, I can really feel it in my core as the action flows back and forth. It's a great ab workout.

When I do resistance training at the gym, I usually alternate between upper body workout one day and then lower body work on the next day. That way, you give your body a chance to rest between workouts. On the Trikke, I can change up my emphasis a little between upper and lower body, but it's not the same as when lifting. You really can't rest without giving Trikking a rest.

Is a couple of hours a day too much?