Russian Twist (on stability ball arms straight)

How to perform it

Step-by-step instructions

1. 01Walk forward on a stability ball until the head and upper back are supported, hips lifted, and feet planted wide enough for balance.
2. 02Extend both arms straight above the chest with the palms together.
3. 03Rotate the ribcage and shoulders to roll onto one shoulder while the hips stay high and level.
4. 04Return the arms above the chest, then rotate to the opposite side.
5. 05Alternate equal controlled repetitions without letting the knees, pelvis, or ball drift.