5 Healthy Reasons to Go Outside

The weather is cooling and sunny days are dwindling, so many sun lovers are heading indoors. You might want to reconsider, according to advice from Harvard Medical School.

Most Americans spend 90 percent of their lives indoors, and people tend to spend less time outside as they age. But are you hurting your health by spending so much time cooped up? You could be, say the Harvard experts, who offer five potential health benefits of spending more time in the great outdoors.

1. More vitamin D

Your body can produce generous amounts of vitamin D, often referred to as the "sunshine vitamin," simply by exposing your skin to the sunlight. Recent studies have shown vitamin D may provide protection from many ailments, including heart attacks, cancer, stroke, and depression.

One problem is that although wearing sunscreen protects the body from skin cancer, those same ultraviolet B (UVB) rays, stimulate the body to produce vitamin D. Not using sunscreen for short walks — but adding it when you're going to be in the sun for an extended period of time during the middle of the day — can be a happy middle ground. You can also supplement your diet with vitamin D pills. Recommended dosage ranges from 400 to 1,000 IU per day.

. Burn more calories

People who spend time outdoors tend to exercise more. British studies found that children double their physical activity when outdoors. And since studies show American children spend more than six hours a day indoors watching television, playing video games, etc., spending more time outdoors can help combat the growing epidemic of childhood obesity, and also help adults to pare pounds. While walking and biking are great exercise, raking leaves also gets the body moving.

3. Be happier

Many people suffer from seasonal affective disorder (SAD), a type of depression that is usually associated with a lack of sunlight in the fall and winter months. In addition, British researchers at the University of Essex believe that exercising in nature, something they call "green exercise," benefits mental health. Their theory fits research that shows mental benefits from living close to open, green spaces.

4. Better concentration

Studies of children with ADHD have suggested that outdoor exercise helps them concentrate better. And a 2008 study found that children with ADHD had higher scores on a test measuring concentration after a walk in a park than after walking though a downtown or residential area. Harvard researchers admit it could be a stretch to apply the research to adults, but add that trying some outdoor activity in as green an area as possible won't hurt.

5. Faster healing

A 2005 study at the University of Pittsburgh found that spinal surgery patients needed less pain medication during their recoveries if they were exposed to natural light. This study backed up an earlier study by researcher Robert Ulrich which found that patients whose hospital rooms looked out a window at a view of nature had speedier recoveries than those whose windows faced a brick wall.