Due to the genre of this dance being a Charleston its very much about being nimble on your feet and coordination. I have added leg strengthening with the squats (but please don’t do these through one leg if you have problems with you knees, keep to side taps if this is the case) . In the later part of the exercise try to get your knees up as far as you can to work those quads. Keep up the energy within this to add to your cardio minutes