Feeling rundown; maybe a little depressed?

You may not need a nap or medicine. In fact, the key to better health could actually be in the bottom of your dirty laundry pile.

A study published in Thursday’s British Journal of Sports Medicine said as little as 20 minutes of physical activity a week improves mental and physical health, although the greater the activity, the more benefit.

Physical activity and exercise isn’t always the same thing, the study’s authors said. Physical activity includes cleaning, housework and walking up the stairs.

"There's such a pervasive feeling in this country that, if there's a problem, there's always a pill to fix it," said Dr. Suzanne Steinbaum, director of Women and Heart Disease at Lenox Hill Hospital in New York City. "This study is just reminding us that it doesn't take much to actually have an effect even on your mood."

Click here to read the study.

Physical inactivity leads to increased risks of cardiovascular disease, metabolic diseases (diabetes, gallstones), cancer, immune dysfunction and Alzheimer’s, according to the study.

The study proved constant physical activity also promoted self-esteem and self-perception, reduced anxiety and feelings of loneliness, as well as aspects of cognitive function.