An exercise physiologist studies the human body's physiology during exercise and physical exertion. He or she uses different tools to study the body systems and how they respond to the stimulus of exercise. This allows the physiologist to gather information for the understanding of the patient, athlete, or study being conducted. A physiologist works in many different types of environments to help carry out the study of exercise and how it affects the human body. Using different types of equipment, they observe the human body through the rigors of exercise to understand how it functions and how this function varies between different people. They then calculate the exercise data to complete reports on their patients.