When you sleep you take slow, regular breaths. However, your breathing rate increases during REM sleep. That's when we usually have our dreams. During this stage of sleep, breathing becomes shallower and less regular.
When you exercise, your heart and lungs work harder to provide the extra oxygen your muscles require. Regular exercise strengthens your lungs and heart in the same way that it strengthens your muscles.
Physical activity increases during exercise, and muscle cells respire more than they do when the body is at rest. During exercise, the heart rate increases. The rate and depth of breathing increase, allowing more oxygen to be absorbed into the bloodstream and more carbon dioxide to be released