The Russian twist is a great underrated ab workout for people of all fitness levels or ages and can be scaled harder or easier with a heavier or lighter medicine ball. Even with no weight at all ...

Hold a weight or medicine ball and twist your torso from side to side. Complete three sets of 15 reps on each side. Bicycle crunches target several abdomen areas at once, perfect for building hula ...

To do Russian twist, sit on a mat ... Stand with your feet shoulder-width apart, maintaining a weight or medicine ball with ...