"Dirt Is Good", it's all about the science...

(Below is a study that we used on a recent airing of our radio show "Get Moving Charlottesville" Gill/Francesca)

Having to deal with bone, muscle and joint pain is one of the main reasons we become inactive. Less muscle strength, loss of bone mass and joints that are less flexible with reduced range of motion are changes that contribute to the discomfort.

"Aerobic activity is important for fitness, but cross training activities can help manage the any arthritic condition by minimizing the compressive forces surrounding the joint," says Bob. "Proper strength training is the most important cross training activity for an arthritic joint. If a high level of strength is maintained, the muscles help dissipate the forces around the joint."

You also may be able to lessen these effects by changing your running surface. In a clinical study of 4,000 runners, 20 percent of the leading causes of injury were "improper" running surfaces.

Running and jogging jar the body and joints. Each time the foot strikes the ground, a certain amount of energy travels back up the leg and is absorbed by the musculoskeletal system. Softer surfaces transfer less energy while harder surfaces transfer more energy. Running on hard surfaces such as concrete sidewalks or asphalt streets can increase the risk of injury. Softer surfaces, such as grass, dirt or synthetic tracks are easier on the joints and more forgiving.

Running Surfaces (Rated by Runner's World from Best to Worst)

1. Grass
2. Wood Chips
3. Dirt
4. Cinders/ Decomposed granite
5. Synthetic Track
6. Treadmill
7. Asphalt
8. Sand
9. Concrete (approximately ten times harder than asphalt)
10. Snow

If you choose a softer running surface, be aware that some off-road surfaces are irregular and may require an increased range of motion from the foot and ankle. You may need to purchase additional shoes, based on the type of running surface you will be using.

We should note that based on the study above, many people may now choose to get off the sidewalk, which is concrete, and instead run on the street that's made of asphalt. While your knees and joints will thank you for it, running in the road presents safety challenges you previously didnt have to think about.

Be sure to watch out for cars and its a good idea to run against the traffic. You might want to leave the music and earphones at home, too. Audio players cut off traffic noise and other sounds in your surroundings that may do you harm. In addition, remember that asphalt streets tend to slope towards the curb. You may want to alternate directions for balance or find a flatter asphalt surface.

If your legs yearn for dirt and grass, Central Texas is rich with trails just waiting to be explored. Runtex, The City of Austin Parks and Recreation Deptartment and the Texas Hill Country Information Service have created over 60 colorful maps of greenbelts, parks and trails . Not only does this give your knees and joints a rest, it also varies your surroundings, which can only improve the experience and keep you interested in running for a long time to come.