If you're feeling sluggish and rundown, coffee or tea may not be the answer. A short trip outdoors may work a lot better.

Studies have shown that even brief exposure to nature has various health benefits. What's shown up most often is an increased feeling of well-being. But it's very hard to show that this is actually due to nature. Just getting to a natural surrounding involves physical exercise and that could be responsible for improved mood. Similarly, in group outings, the social component alone could be responsible.

Their conclusions were that being outside in a natural setting for just 20 minutes boosts vitality; people feel more alive.

A team headed by a University of Rochester psychologist recently ran a series of studies designed to tell if the feel-good effects of exposure to nature were really due to nature or to some other factor or factors. Their conclusions were that being outside in a natural setting for just 20 minutes boosts vitality; people feel more alive.

As one researcher put it, nature is fuel for the soul.

People don't always agree about what nature is, but they know what it isn't: bricks and mortar, gadgets and paperwork, automobiles and air conditioning.

The researchers conducted five separate studies on 537 college students. These ranged from the real to the imaginary, from the participants tracking their mood and activities over two weeks in a diary to laboratory experiments where students imagined themselves in various natural and unnatural settings. And the results consistently showed that individuals felt more energetic when they spent time in natural settings or imagined themselves there. Not surprisingly, being there worked better than imagining being there.

One particularly interesting result was that a natural setting had an independent positive effect not seen from just being outdoors; standing in a parking lot wasn't nearly as good as standing in a field.

These results pose some practical problems for people who live in the urban jungles we call cities. There's just not that much nature to be found. To urban dwellers, nature mostly means parks. But even in cities, nature still exists; it just takes some effort to find it. Secret gardens bloom in obscurity. Grass unexpectedly pokes up through asphalt. And if all else fails, there are always house plants.

Twenty-first century living can be draining. Communing with nature, however briefly, helps you recharge.

An article detailing the studies was published in the June, 2010 issue of the Journal of Environmental Psychology.