One adaptation that improves with cardiorespiratory fitness is that the lungs become more efficient at bringing in large volumes of oxygen-rich air.

American College Of Sports Medicine

A leading organization in sports medicine and exercise science, promoting and integrating scientific research to provide educational and practical applications of exercise science and sports medicine.

Moderate Intensity

An activity level that elevates the heart rate and induces sweating, such as brisk walking or light cycling, but allows one to carry on a conversation.