If the resistance is progressive – either with bands, weights, or body-weight resistance – than yes, you will build strength. However, most of these type routines do not involve weights that challenge your muscles to the point where they are strengthened.
Consistent stretching of various muscles will improve your flexibility. Most of these type workouts involve very focused stretching routines with lots of breathing exercises to enhance the movements. However, the key to flexibility is consistency. Muscles need to be properly warmed up and stretched regularly to maintain and enhance a joint’s range of motion.
Most of these workouts do not provide enough exertion to get your heart rate up and therefore burn a lot of calories. So they are not the best fat burners out there. However, with any focused movement you are burning calories.
Cardio: WHAT DO YOU THINK?
If your level of exertion is maximized, than your heart rate is up to the point where you’re building cardiovascular strength. However, let’s be honest: for the most part these type exercises do not – and in many cases should not – stress your heart to that point.
Reduce stress: ABSOLUTELY
Learning how to breathe correctly, meditating and focusing on your inner-self are all great ways to finding peace with yourself and your world.
I believe that most mind-body routines are great ways to improve overall fitness and to help you in many other areas of your life. You will notice all kinds of results. But always ask yourself the two most important questions of all: 1) Is it what you want? And most importantly: 2) Are you having fun?