As described in Section 1 (Physical and Mental Benefits of Exercise section), anyone who completes exercise can benefit in numerous ways.
But what is exercise and can anything you do off of the couch count as exercise? To determine this, first we need to discuss the similarities and differences between Physical Activity, Physical Fitness, and Exercise.
They are quite related, but they are also somewhat different.
Physical Fitness: the ability of the body to adapt to the demands of physical effort
Your body has a fantastic ability to adapt to whatever demands you place on it through physical activity.
Physical Activity: any movement of the body that is carried out by the muscles and requires energy to produce
Not all physical activity will make you physically fit. Just you getting out of bed this morning, brushing your teeth, eating breakfast, etc. makes you more physically active compared to someone who sleeps in bed all day. In order to become more physically fit, you have to engage in exercise.
Exercise: a planned, structured, repetitive movement designed specifically to improve or maintain physical fitness
But that term, exercise, has some real negative connotations for some people. Some consider exercise to be extremely hard work or even torturous.