Overhead Dumbbell Lunge

Grab a pair of dumbbells and hold them straight above your shoulders, your arms straight and elbows locked.  
 
Stand with your feet hip-width apart. Keeping your torso upright, step forward with your left leg and lower your body until your front knee is bent 90 degrees and your rear knee nearly touches the floor. 
 
Push yourself back up to the starting position, and repeat with your right leg. That’s one repetition.