In a study, women did isometric exercises for their stomach, back, shoulders and arms while researchers measured muscle activity. The results? Shoulder extensions made middle-body muscles contract most -- apparently they work extra hard to stabilize your trunk when your wings are flapping.
Some more ways to get your midsection, and whole body into mint condition:
- Roll out the ball. For strong core muscles and better balance, do tummy and back toners on an exercise ball.
- Add resistance. Use weights or resistance bands for extra burn.