Science is clear: exercise doesn't help that much for losing weight. However, it does help with a staggering variety of other conditions. Whether it's osteoarthritis, rheumatoid arthritis, heart health, cholesterol levels, depression, chronic fatigue, or even the symptoms of Parkinson's disease, quality science has demonstrated that exercise helps.
And as Aaron Carroll explains below, the amount of exercise in these studies is pretty moderate. A half hour of simple brisk walking, done five times per week, gets you most of the way there. No need to kill yourself with CrossFit or Navy SEAL routines to stay healthy. Ryan Cooper