This document discusses ways to improve lung function after quitting smoking. It finds that lung function can improve by over 15% within 8 weeks of stopping smoking. Regular exercise, deep breathing exercises, a healthy diet with vitamins C and E, and avoiding smoke-filled environments can further help lung recovery over time. The lungs will gradually heal and repair themselves after quitting, though it may take over a year to fully recover lung capacity to levels of a non-smoker.