Photo credits: Top, James Michelfelder.
1. Lie back on a flat or incline bench holding a pair of dumbbells over your chest with your elbows slightly bent and your palms facing each other.
2. Separate your hands and lower the dumbbells directly to each side until you feel a stretch in your chest. At the bottom of the move, your palms should face the ceiling or slightly inward.
3. Return to the starting position.
4. Separate your hands and lower the dumbbells so that they form a 45-degree angle with your body. That's one rep.