These work the large back muscles (responsible for giving you that coveted V-shaped back!), back of the shoulder and biceps.
Get into a lunge position, bending forward slightly. Dumbbells in both hands, hanging down by your sides. Bend your elbows and pull them upward and backward in a rowing motion. Slowly lower the arms back to start position.
Do one set of 16, rest and repeat.
Photograph: Carlo Allegri/Getty Images
Also read: A fitness routine for when you're pregnant!