Doing exercises on a continuous basis. The only way you can do to achieve result. Otherwise, the problems will come back to you after some time and all the efforts done before will be wasted. You should start with breathing exercises. Lie on your back and bend your knees. One hand lay on his stomach, the other on the chest. First, breathe in belly, inhale and exhale the lock, holding his breath for a few seconds. Then breathe in the chest. Exhale arms out to the side, and on the inhale, grasp the chest with his hands. Proper breathing is the first step on the way to a straight posture.
Complete the following exercise. You will need a bag filled with sand. Weight it needs to be no more than 1 kg. bag on your head and lean back against the wall. Your hands should be severely stretched at the seams. The back should be straight. So wait about 5 minutes. Subsequently, increase the time. Do this exercise every day. it will allow you to lock the position of the back.
To strengthen your posture you need to train the abdominal muscles and back. Lie on your stomach, then lift legs, arms and head from the floor. Fix this position for a few seconds and then again repeat the same. This exercise will allow you to strengthen the abdominal muscles. Lie on your back and bend your knees, the foot should be on the floor. Hands pull along the trunk. Then lift and lower hips, not lifting with the hands from the floor. When you sit at the table, try to keep a straight posture. Sitting full chair, and for convenience keep your hands on the table. In the lumbar region you should have a small deflection forward. At first it's very hard. But later, when your muscles get used to it, it becomes easier, and posture.