Answer:
Human body muscles need the energy to do the task. The body fuel is carbohydrate, proteins, fats that help the body in regulating the body system. When a person works out in the gym or anywhere then the blood flow in the body gets warmed up which increases the core temperature of the body. The amount of energy generated depends on much you work out. More heat produces when you work hard. When we work out our body heat production increase 15 to 20 times higher than the resting level. When a person's core temperature increased the blood shifted to the skin that allows the skin to radiate more blood. The body will maintain the body's metabolism rate and energy of the body to maintain the balance.