I'm Renee Byrd. And this is leg curls on a stability ball. The stability ball requires to balance your weight, therefore engaging multiple muscle groups at once. The leg curl is going to target your thighs and your lower legs. However, we're also going to engage your abs, your hips and your lower back. So the first thing you want to do is get into a reverse plank position taking your heels and the back of your shins and placing them on your stability ball. So you're going to place your hands along your side. You can place them right next to you or even a little bit wider if that's more comfortable. The other thing you want to do is really engage your hips, your pelvis and your lower abs, lifting into that reverse plank position. From this point you're just going to roll the ball in all the way until both feet are flat on to the ball and then you're going to release it. You're going to repeat this exercise for about 15 reps and do at least 3 sets. If you find that this has gotten just a little bit not as challenging as it was when you first started. What you can always do is lift one leg and take it to a one leg. Again, making sure that you go all the way in until your feet are flat against the ball and then all the way out until your heels and the back of your shins are replaced on the ball.