Exercise increases the blood flow in one's heart and strengthens the heart muscles. During exercise more blood gets pumped into the lungs to enable increased oxygen absorption. This oxygen is then carried to the body muscles engaged in exercise, usually the legs and arms. When a person exercises, both his heart rate and his breathing rate increase considerably, making his heart and lungs work harder.
The American Heart Association recommends that everyone should do cardiovascular exercise for a period of at least 30 minutes or ideally 45 minutes on a daily basis. This benefits the heart as well as the lungs. The risk of developing high cholesterol and related health issues is reduced significantly, and a person's vital lung capacity is improved during and after exercise. When a person is just sitting, his breathing rate is about 15 breaths per minute. However, an athlete who undertakes a rigorous exercise regimen can have a breathing rate that reaches 40 to 50 breaths per minute. Taking more oxygen into the body assists in meeting the increased demands of a person's muscles during exercise. To obtain all these positive effects, even people with heart and lung diseases are recommend to do small amount of exercise if possible to improve their heart and lung functions.