An exercise that'll work several muscle groups

This exercise published in Los Angeles Times can be done at home, only two dumbbells are needed. Quoting from LA Times:

"Step 1 Hold a dumbbell in each hand and stand with your right leg in front of your left leg. Bend your right knee, maintaining a straight back. Starting with your arms down, lean forward with your upper body and bend your arms, bringing your hands near your ears. Extend your arms fully until they are overhead. Pause."

"Step 2 Stay in this forward lean-lunge position as you slowly lower your straight arms toward the floor and then lift them up to the back as far as you can. Concentrate on pulling your navel toward the spine to support your back muscles throughout the exercise. Repeat three times, step together and repeat with your left leg in front."

Image sources are the following links:

http://www.latimes.com/media/photo/2008-03/37011515.jpg

http://www.latimes.com/media/photo/2008-03/37011509.jpg