Caffeine drinks A cup of coffee, soda, tea, or other drink with caffeine can help your airways open. A small amount of caffeine can help you breathe better for up to 4 hours. Large amounts of caffeine can be toxic if used over a long period of time. The most effective way to increase lung capacity is through exercise. The more oxygen-rich your blood is, the more likely your lungs are to grow stronger and your overall health will improve. With exercise, you'll get bigger muscles that can work harder and longer. This will allow you to take in more oxygen and expel more carbon dioxide. In addition, being active helps reduce your risk of developing conditions such as asthma, chronic bronchitis, emphysema, and heart disease. If you're not active, it's important to start now. Find an activity you enjoy such as running, biking, swimming, or walking and practice doing it regularly. As you become fitter, you'll find yourself needing to breathe more often during activities so that you have enough time to complete them. This is normal and should never cause pain. If you do experience pain when you breathe, stop what you're doing and rest until this goes away. Don't try to push through it because this only makes things worse.