A stability ball is a powerful ally in your quest for flatter abdominals and a cinched waist. Not only can it make that plank or crunch more challenging, it also ups the ante on standing abdominal work such as the Russian twist, demonstrated here by celebrity trainer and group fitness instructor Amy Dixon, who uses the move on her "Give Me 10 Core Cuts" DVD.
What it does
This exercise tones your core, loosens your hips and gets your heart rate up, allowing you to burn more calories than you would with some other floor exercises. It's also a great warm-up for other exercise.
What to do
Stand in a sumo squat with legs wider than hip distance, extending the ball in front of you with both hands. Rotate to the left, keeping the ball extended out in front of you as far as you can and pivoting on your right foot with your heel in the air. Then twist back through the center to the far right as you pivot on the left foot. Inhale as you move through the center; exhale as you rotate to each side. Long arms and greater range of motion are what determine the intensity of this exercise. It can be made easier by bringing the ball in closer to your chest.
Do three sets of 12 repetitions.