[Lauren_]

I think dancing with a weight belt on is extremely dangerous for your knees. Saiidi, even without a hip belt, is questionable for bad knees, depending on the surface you're working on.

If you're looking for more cardio, for endurance, I'd do more traveling. Don't dance in one room, dance through the whole house, visit every room during a song. And keep your arms at or above heart level.

If you're looking for a workout for your muscles, I'd use workout activities.

I'm not sure I understand why you want to increase dance speed?

In my mind, I work out with crosstraining activities (yoga, weights, cardio) in order to build the stamina, strength and flexibility so my body doesn't get in the way of creating the dances I can imagine.

Dancing is not really meant to be a conditioning activity in itself (unless you're a sedentary person just beginning to do cardio, it's certainly better than couch-sitting and more fun than walking in place).

It's not safe to build your body by dancing. Build your body for dancing instead!

(I'm starting to lecture, thanks for letting me say my piece. I promise not to repeat myself again on this thread.)

FWIW, I'm an ACE certified fitness instructor, and a senior in a university kinesiology program. And a Yoga Alliance 200-hour RYT. There are other certified fitness individuals on the board, I hope they'll check in with their opinions.