This exercise is very effective for the back of your arms. It also works your shoulders, core and legs. There are so many different variations of this exercise. You can use chairs or a sofa if you are working out from home. You can raise one leg straight out in front of you. I have chosen to do it on the floor with with one leg crossed over the other.
Start by sitting on the mat with your feet out in front bending knees at a 90 degrees angle. Your hands should be behind you facing down. Place your left foot over your right knee and with your elbows pointing behind you raise your shoulders untill they are almost straight and lift your glutes. Keep moving up and down using your arms, making sure your glutes do not touch the mat and keep your core pulled in tight througout the entire exercise. Try to do 2-3 sets 8-16 reps or just do as many as you can.