This is a great exercise to add into your routine, because its an AMAZING workout that requires 0 equipment. All you do is put your hands behind your head while you lower into a kneeling position and then return to standing. You only need to do a few reps of these before your heart rate reaches cardio levels. I did three rounds of 16, 14, and 12 reps as each subsequent round gets harder. At the end of each round, my heart rate was a solid 140 bpm. While this is a great leg workout, it’s also a great core workout. You have to really maintain good posture to keep your balance, since your hands are up behind your head. Usually I use my arms as counterbalances when I’m doing exercises that call for balance, and that is just not an option with this particular move.