Don't underestimate this deceptively simple move. "Besides improving posture, it builds the kind of strength that helps you lift things overhead with ease," says Ballantyne, by targeting your delts, back, and core.
The Setup: Hold a broomstick overhead with a wide-grip. Keep your abs braced and squeeze your shoulder blades together.
How to Do It: Keep your chest lifted as you squat as low as possible (below parallel) without losing your form while maintaining the stick overhead. Return to start position.