If you've ever come home from a brisk walk feeling reinvigorated, you're not alone. Research shows that this is just one of many benefits of exercising outdoors.

Working out in a natural environment also can be more physically challenging, making your body work harder and bringing greater fitness results. This happens when, for instance, you're walking, hiking or running on natural terrain, which can vary in evenness and require more exertion than on a flat surface, such as a treadmill.

According to the American Council on Exercise, other outdoor factors, like wind resistance, actually enable you to burn more calories. If, on the other hand, the wind is at your back, pushing you along a bit, you engage certain muscle fibers needed to develop strength and definition.

One study found that people get a variety of psychological boosts from building up a sweat outdoors. Participants were in a better mood and had more energy and less stress afterwards. They simply liked doing the same form of exercise more when they did it outdoors, in nature.

There also  are benefits from the social interaction of exercising outside with a friend or in a group -- the enjoyment you feel makes it more likely that you'll plan more outdoor workouts.

If you have children, exercise with them to show them that fitness activities are fun. Family hikes and ski trips are great, but just being active with them at a park or playground counts, too.

And if you're caregiving for elderly parents, they, too, will benefit from time spent outdoors.

Get the entire family involved.