Mixed Grip Chin Up

Grasp a chin up bar with your hands shoulder-width apart. Use an underhand-grip with one hand, and an overhand-grip with the other.

Hang at arms length, and cross your ankles behind you. Now pull your chest to the bar by bending your elbows and squeezing your shoulder blades down and back.

Once the top of your chest touches the bar, pause, then slowly lower your body back to the start.