Regular exercise produces good muscle tone . Just to maintain good posture, some muscle fibers must always be contracting. Muscles exercised frequently do a better job at everything, including holding the body erect.
Good tone makes a muscle both ready to move and resistant to fatigue .
The heart muscle is the greatest beneficiary of exercise. With regular exercise, the heart grows stronger. It draws more blood and oxygen through the coronary arteries and increases the amount of blood it pumps with each beat. A larger stroke volume means that the heart can pump the same amount of blood with fewer beats. This potentially adds years to its life-span.