Physiology is the field of biology that studies the biophysical and biochemical functions of living organisms, including humans or in simpler terms, the way an organism or organism functions.
 

Specifically, Exercise Physiology focuses on the way our body responds to exercise during exercise. It is the study of acute reactions and chronic adaptations to a wide range of exercise conditions.
 

People have a great ability to consume energy for long hours during extended exercise. This energy expenditure is very high compared to the basic metabolic rate of the rest of the adult human body. This rate varies somewhat depending on size, gender and age.

The total energy expenditure due to muscular energy consumption during the day is much higher and depends on the average level of physical activity and exercise. 
 

Thus, exercise, especially if maintained for very long periods, dominates the body's energy metabolism. 
 

The energy expenditure of physical activity is strongly correlated with one's sex, age, weight, heart rate and maximum oxygen uptake during physical activity.