Regular exercise increases the number of capillaries (small blood vessels), thereby improving the blood supply. It also increases the mitochondria within the cells, which are responsible for the release of energy. Thus, a fit person can efficiently transfer oxygen to different parts of the body and also release energy efficiently.
Regular exercise makes a person more efficient at work and enables the person to work longer hours without getting tired. Body fat gets redistributed through regular exercise. During exercise sessions that are longer than 30 to 35 minutes, body fat is used more than carbohydrates for deriving energy.
As muscle mass increases, the lean body weight increases as compared to body fat. Central obesity decreases, insulin resistance is lowered, HDL cholesterol increases, blood pressure goes down, diabetes gets controlled and chances of formation of blood-clots minimised.