improve your posture
There are many ways by which you can improve your posture through exercise. The usual running and aerobic exercises may be good for your lungs but it will not improve your posture. It is important to choose the right exercise for your posture. Not only will a wrong choice of exercise do nothing to help; it can actually aggravate problems with your back.
The goal of exercises meant to improve your posture is to balance out the rest of the activity for the day. If you are in front of the computer a large part of the time, you are probably slouched in your chair with your arms hanging from the keyboard and your neck stretched out towards the screen. You need exercises that will balance that out. You can either stretch the front of your body more, or strengthen the back more. A combination of the two is usually the best.