Toned arms and shoulders look great in sleeveless tops, but they also serve a more essential purpose: They help move the larger muscles in your chest and back that make it easier to stand up straight. When you strengthen your arm muscles with light weightlifting, you can improve your posture without building bulk. This easy exercise is courtesy of Gregory Joujon-Roche, Hollywood trainer and author of One Body, One Life (Dutton, 2006).
Seated Bicep Curl
Benefits: Strengthens the biceps and the inside of your arms.
Sit on a chair or bench and hold a dumbbell in each hand at yoaur sides. (If you're a beginner, choose weights that are 2 to 8 pounds each. If you've been lifting weights for a while, you may need more than 8 pounds to feel the full contraction.) Roll your shoulder blades back and turn your hands so that your palms are facing up.
Squeeze your pinkie into the dumbbell and, keeping your elbows at your sides, slowly curl both weights up to shoulder height. Then lower the weights back to starting position, but don't rest them on your thighs. Repeat.
Rx: Do 3 sets of 20 repetitions.