Posture often falls apart due to time spent crouched in front of a computer, cradled in a couch or confined to a chair. You have the best intentions when you work out, but hitting the gym to counter all that time spent sitting can also work against your posture. Work the muscles you see in the mirror -- namely the chest, abs, biceps and fronts of the shoulders -- at the expense of your upper, middle and lower back, and you'll enhance a rounded forward look.
It's an easy fix, though — include just a few moves regularly at workouts and during your down time to keep your shoulders pulled back and down. You'll increase chest flexibility while strengthening the posterior deltoids, trapezius and rhomboids.
Your first order of business is to strengthen the backs of the shoulders, known as the posterior deltoids. You also want to train the large diamond-shaped upper-back muscle called the trapezius and the rhomboids, positioned at the back of the shoulder blades and responsible for scapular retraction.
Integrate several of these moves into your regular shoulder workouts or back workouts, working up to three sets of eight to 12 repetitions.
Opening up and stretching the front side of your chest undoes forward rounded posture and trains your shoulders to stay more integrated down your back. Do these moves multiple times per day to seal in the benefits.