It keeps you physically fit and able.

Without regular activity, your body slowly loses its strength, stamina and ability to function properly. It’s like the old saying: you don’t stop moving from growing old, you grow old from stopping moving. Exercise increases muscle strength, which in turn increases your ability to do other physical activities.

It helps keep the doctor away.

Stand up when you eat your apple a day! Too much sitting and other sedentary activities can increase your risk of heart disease and stroke. One study showed that adults who watch more than 4 hours of television a day had an 80% higher risk of death from cardiovascular disease.

All of this can add up to fewer medical expenses, interventions and medications later in life!

Source: Why Is Physical Activity So Important for Health, and Well Being?