If you get tired of floor exercises or need something you can do at work for your abs, seated rotations are a good choice. You can work your obliques, as well as your lower back, and holding the weight adds intensity and will involve the shoulders, arms and chest as well.
- Sit tall on a ball or chair and hold a medium weight.
- Begin the movement with the weight at chest level, shoulders relaxed.
- Keeping the hips and knees facing forward, rotate the torso to the right as far as you comfortably can. Focus on squeezing the muscles around your waist.
- Rotate back to center and then to the left, keeping the movement slow and controlled.
- Continue alternating sides for 1-3 sets of 10-16 reps.