"Improving posture means changing a habit and this takes time, repetition, and practice," St. John told POPSUGAR. Even small changes can make a difference. "Stand on the centre of your feet or sit on the centre of your sit bones for one to five minutes at a stretch, three times a day," she said. "Set a timer on the computer or phone and concentrate for that short period of time. The body may need to adapt to the new position slowly so give it time."
You can also incorporate stretches while you work. "Stretch the chest by clasping the hands behind the back and rolling the shoulders back. Or, take hold of the sides of the chair seat and press the chest forward until a stretch is felt," St. John said. "Do this several times a day to open the chest and strengthen the upper back."