Running and Knees
The knees are put through a rigorous test with every stride you take while running. Each joint must withstand the pressure of up to eight times your body weight with each running step. That equates to approximately 1,200 lbs. of force for a 150-lb. individual. The distinct running style of every person can add additional stress on the knees if bad running technique is used. Furthermore, the repeated jarring can exacerbate any past knee problems or injuries. All combined, these factors could make for a good argument against running altogether.
Even though an unpaved trail may not be right outside your doorstep, finding one near you may be worth the effort to help reduce the amount of stress your knees undergo when you run. Compared to paved streets or trails, unpaved trails are generally softer and provide less resistance during running. Your feet sink in slightly upon impact on an unpaved trail, which partially absorbs the force of impact with each stride. This helps cut down on the overall stress your knees must endure -- something that can make running long distances a noticeably more pleasant experience for you.
Additional Trail Benefits
Trail running not only helps save your knees from intense jarring, it also intensifies your overall workout. Trails are almost never straight and even. They generally include various inclines and declines, roots sticking out of the ground, tree branches, water obstacles such as streams and puddles, and a variety of other natural elements. Such terrain typically doesn't allow for steady, paced running. Trail running incorporates lots of jumping, twisting, directional changes and pace variations. The natural obstacles can give you a more effective overall workout and help improve your sense of balance and reaction time.
Trail Running Surfaces
Trails can consist of a variety of surfaces. Some are simply worn dirt trails that were formed by hikers and other runners. This type of surface is generally packed down and moderately hard when dry. Such trails are often narrow, which means you'll have to keep an eye out for branches or rocks. Many parks or rural areas feature horse trails that can be used by runners. These are easier to run when the gravel is finer so the terrain is easier on your ankles. Wood chips are another popular trail surface and make for great cushioning that doesn't deteriorate even when wet.
By: Dan Harriman