Yoga

It would depend on what type (cardio, meditation, etc.) and your efforts. Try the heart rate monitor during to be able to tell for sure.

I don't know, but I consider exercise an extra on top of the calorie deficit from food reduction, and yoga tends to burn far fewer calories than aerobic activity. I think people who keep trying to make yoga into a calorie-busting practice have entirely the wrong idea. It's supposed to be slow, fluid, meditative.

Hmm - yes yoga is supposed to be slow, fluid and meditative, but it is not wishy washy hand waving. That slow, fluid movement can, with the right intent, build substantial strength throughout the whole muscle and not just at the explosive beginning and contraction at he end of a weight training movement. A good Yoga practitioner will be able to hold a movement at any point in the move; whatever it may be.

Very seldom does a weight trainer pause or slow down an exercise; especially when lifting heavy so the strength can become (not always) plyometric rather than weight bearing.