I understand the idea of, and the reason behind, a *rest day* between heavy workouts of each muscle group but, I'm wondering if body weight/resistance training - that is killer to get through but doesn't leave you sore the next day - requires a rest day as well?

I'm currently doing Fluidity three days a week (which is basically a portable ballet barre with a DVD program of full body exercises and stretches to follow) with a dance video twice a week on alternate days for cardio and one day of rest. Every once in a while my schedule gets a little dicey and makes it tough to stick to this exact schedule. I'd rather skip the *dancey* workout than the Fluidity but am not sure if doing it two days in a row would actually be of any benefit or if I'm better off keeping my every-other-day schedule going and take an extra rest day if I really and truly can't fit it in.

In my own personal non-professional opinion ( do you still want it?) I would consider the rest day more important for extra weight bearing exercise. If you are doing a pilates style exercise, I wouldn't worry about it as much as if you are using barbells and dumbbells. The rest period is so your muscle can repair and become stronger. If you don't feel it the next day at all, then you may not have done enough to warrant a rest period.

I'm not familiar with your program, or maybe I could help more. I do know that Push TV had a body weight program that was a replacement for weight lifting. That one I did use a rest period for. When I did Kathy Smith Pilates (gentler than Push TV), I did that in between upper and lower body days.