Physiology is the study of the function of tissues (e.g., muscle, nerve), organs (e.g., heart, lungs) , and systems(e.g., cardiovascular).Exercise physiology extends this evaluate the effect of a single bout of exercise (acute exercise) and repeated bouts of exercise (i.e., training programs)on these tissue, organs, and systems. In addition, the responses to acute exercise and raining and may be studied as high altitude or in extremes of heart and humidity to determine the impact of these environmental factors on our ability to response and adapt to exercise. Finally, studies are conducted on young and ole individuals, both healthy and those with disease, to understand the role of exercise in the prevention of or rehabilitation from various chronic diseases.