Runners frequently ask about running on pavement and how this activity can affect their knees and other joints. There’s certainly a lot to consider with this question. First, the force applied through your body each time you land can equal about 3x as much as your body weight. Think about a 150 pound runner and do the math. This person will experience approximately 450 pounds of force with each stride! Pavement is a rather unforgiving surface that will not absorb much of that force during a run (one reason good shoes can be so important!) that can include thousands upon thousands of landing impacts. You can always avoid some of the force associated with pavement by choosing a track or by running on a trail. While discussing trail running one day recently with someone at Colorado Running Company here in Colorado Springs, I was presented with an interesting question. Which is better for your body: running on a trail or running on a paved surface? I’m going to take a classic answer on this question by stating that…it depends. While both options are good, there are certain injury risks to prepare for with either surface.
We already talked a little about the physics involved with pavement. There is that high impact force associated with each step that can take its toll. I’m not saying that makes this option bad. In fact, our bones are meant to take on that type of force. When they do, the bones become stronger. It’s just like building muscle strength with weightlifting. But, just like weightlifting, if technique is bad and adequate rest isn’t provided, injuries can occur. Poor form and repeated stress of the run could potentially lead to stress fractures, which are small breaks in the bone of the leg.
Additionally, if someone has some types of joint issues such as arthritis, where the cushion-like surfaces of the joint have started to wear away, hard impacts are likely to be even more detrimental than it would be for a person with healthier joints. Those impact forces can lead to more inflammation and more pain.
Trail running switches us to a different environment. The rigidness of the pavement has been replaced with softer dirt and possibly the occasional rock. Now our concerns are a little bit different. If you have had frequent ankle sprains, there are so many obstacles that could, literally, trip you up. Being mindful of the divots, tree roots, rocks, and other items on the trail is very important. Also important is preparing the body for these obstacles. A good program to stabilize the ankles will aid in avoiding a sprain.
Changes in elevation are more likely with trail running. The body must be prepared for such changes as well. Make sure you have conditioned your body for both the ascent and descent of the hills and mountains you challenge. Training specific to controlling your descent will be helpful in avoiding overuse injuries to your muscles and their tendons.
Just remember that neither option is bad. Running is a great cardiovascular exercise that provides numerous physical and psychological health benefits. If I’m running, personally I’d rather be doing it while enjoying the views in Red Rocks Open Space instead of going down Colorado Ave, but that’s just me. The most important thing is to be frequently assessing your progress. Be aware of your technique, pace yourself into a gradual increase in distance/pace when first getting started, and make sure your runs are not painful. If you are having pain with running or you aren’t sure how to get started safely with a program (whether this is for the first time or after an injury), speaking with a healthcare professional that specializes in sports is a great resource. If you have more questions about anything you read in this post and want more info, email me at firstname.lastname@example.org or reach out on Backcountry Physical Therapy’s social media pages. Be sure to check back on the website for more blog posts and follow us on social media for helpful tips to keep yourself painfree!