A daily exercise program of at least 30 minutes, attention to weight control, diet and nutrition, adequate hydration and sleep can all help to keep your COPD stable. You can't stop the progression because everyone, even people without lung disease actually lose lung function every year; hence it's progressive; but you can maintain your functioning level relative to people without lung disease. My FEV1 has stayed within about 7 points of where it was in 2000 when I was first diagnosed. That's very stable.