Out with the old, stale air and in with new fresh air. That's the theme of the two most useful breathing exercises—pursed lip breathing and belly breathing—taught by pulmonary rehabilitation specialists to individuals with chronic lung diseases such as asthma and COPD.  Like aerobic exercise improves your heart function and strengthens your muscles, breathing exercises can make your lungs more efficient. 

Why Breathing Exercises Help 
When you have healthy lungs, breathing is natural and easy. You breathe in and out with your diaphragm doing about 80 percent of the work to fill your lungs with a mixture of oxygen and other gases, and then to send the waste gas out. Lung HelpLine respiratory therapist Mark Courtney compares the process to a screen door with a spring, opening and shutting on its own. "Our lungs are springy, like the door. Over time, though, with asthma and especially with COPD, our lungs lose that springiness. They don't return to the same level as when you start breathing, and air gets trapped in our lungs," Courtney explains. 

Over time, stale air builds up, leaving less room for the diaphragm to contract and bring in fresh oxygen. With the diaphragm not working to full capacity, the body starts to use other muscles in the neck, back and chest for breathing. This translates into lower oxygen levels, and less reserve for exercise and activity. If practiced regularly, breathing exercises can help rid the lungs of accumulated stale air, increase oxygen levels and get the diaphragm to return to its job of helping you breathe. 

Pursed Lip Breathing  
This exercise reduces the number of breaths you take and keeps your airways open longer. More air is able to flow in and out of your lungs so you can be more physically active. To practice it, simply breathe in through your nose and breathe out at least twice as long through your mouth, with pursed lips. 
Pursed Lip Breathing Exercise (YouTube)      

Belly Breathing, aka Diaphragmic Breathing
As with pursed lip breathing, start by breathing in through your nose. Pay attention to how your belly fills up with air. You can put your hands lightly on your stomach, or place a tissue box on it, so you can be aware of your belly rising and falling. Breathe out through your mouth at least two to three times as long as your inhale. Be sure to relax your neck and shoulders as you retrain your diaphragm to take on the work of helping to fill and empty your lungs.  
Belly Breathing       

Practice Makes Perfect     
Courtney warns that although these exercises seem simple, they take some time to master. "You don't want to first try these exercises when you're short of breath," he says. "You want to try them when you're breathing OK, and then later on when you're more comfortable, you can use them when you're short of breath." Ideally, you should practice both exercises about 5 to 10 minutes every day.  ARTICLE HERE