Practice yoga. Whether you take a class or buy or rent a DVD to perform yoga at home, practicing yoga will increase your flexibility and improve your posture, increasing your total upper body height. By practicing certain poses, such as the downward dog, you will strengthen and lengthen your upper body, which will make you taller when you are both sitting and standing. In the downward dog pose, you lengthen the spine using your arms while you're positioned on all fours.
Perform upper body stretches. Upper body stretches that round the spine will lengthen your upper body and make you appear taller. Any stretches that round the spine or cause your to extend your legs and arms simultaneously will lengthen and increase the height of the torso and entire upper body.
Stretch your spine by hanging. When you assume a position in which you are hanging, you will stretch out your spinal column, lengthening your upper body. This movement can be done from a pull-up bar at a gym or in your home, or on an ab chair machine.
Develop a routine. Performing yoga or doing stretching exercises won't increase your upper body height if you only do them once or twice. Consistency is required to increase and maintain upper body height. Perform stretches four to five times per week and do yoga for at least 30 minutes three times per week.