For every action, there is an equal and opposite reaction. —Sir Isaac Newton
Newton’s Laws of motion were published about 300 years before the running/jogging boom of the 1980s, but his 3rd Law, stated above, is very applicable for those of us who like to exercise on our feet–particularly if we’re running or jogging. When we run we exert force into the ground (a force somewhere around 2 1/2 times our body weight, for a moderate running speed!), and we know that because of Newton’s 3rd Law, that force is returned back into our bodies. We refer to this phenomenon as IMPACT. Because of impact, the surface we choose to run upon becomes important, because too much impact can lead to both acute and chronic injuries, particularly to the lower leg, ankle, and foot. So, as you trek across Montana this summer, here are a list of surfaces you are likely to encounter, and the pros and cons of each.
Description: Concrete is the most commonly used man-made construction material in the world. Concrete is basically crushed rock and cement. In other words, it’s hard as rock.
- Pros: Most sidewalks are concrete, which means they were made for pedestrian traffic. A concrete sidewalk is a flat, sure-footed surface which is safe from the perils of automobile traffic.
- Cons: Concrete is one of the hardest surfaces you can run on, which means that our running impact is reflected pretty harshly back through our lower legs, joints, and connective tissues.
- Recommendation: Run on concrete sparingly, only when it is your only safe option to avoid heavy traffic. Walking on concrete is fine, because there are less impact forces associated with walking.
Description: Asphalt concrete, also known as blacktop, is commonly used in road construction. The asphalt component is a petroleum-based, highly viscous liquid, which is mixed with particles to form asphalt concrete. Because of this tar-like element, asphalt concrete is much less dense than normal concrete, which means more impact forces can be absorbed by the ground.
- Pros: Because asphalt is less dense and contains a tar-like component, it is a softer surface relative to concrete, and usually provides a flat, sure-footed surface for runners.
- Cons: Asphalt is most commonly found on roads, which means you must take care to watch for traffic and take appropriate precautions. In the summer, the dark surface of asphalt can get awfully hot during the daytime.
- Recommendations: Not a bad surface for moderate mileage, if it is safe from traffic. When running on the road, always run against the flow of traffic so that you can see oncoming vehicles and adjust. Roads with wide shoulders are best. Also, many “shared use” paths for bikers and pedestrians are often made of asphalt. Find out where these paths are in your community and incorporate them into your routes.
Description: There are a wide variety of trails in Montana. Trails cover natural terrain, and may be maintained to some degree. Many trails inside city limits may be very well maintained, and some of the best may offer a cover surface such as cedar chips or some sort of mulch.
- Pros: Many trails offer optimal surface conditions when it comes to impact. Dirt is more forgiving to our musculoskeletal system than either concrete or asphalt. Trails usually offer visual stimulation, and can be more motivating or rewarding to traverse than a sidewalk or road. If you have healthy feet and ankles, running on natural and somewhat uneven surfaces can help you interact with the ground better (proprioception) and strengthen the muscles and connective tissues of the feet and lower legs.
- Cons: Again, trails come in many varieties. Some trails may prove very difficult for all but experienced trail runners, either in terms of elevation gains, or challenging terrain. Trail running is unpredictable–watch for rocks, roots, and ruts! Runners with foot/ankle injuries, weakness, or problems should use extreme caution, or find a more stable surface.
- Recommendations: For those with healthy feet, ankles, and legs, trail running usually provides a stimulating and challenging workout without the pounding of concrete or asphalt. Exception: Trails that have steep downhill grades. But for the most part, go have fun and enjoy! Also, on challenging trails, don’t pressure yourself into running the whole time. There is nothing wrong with what I call a good run/hike.
Description: Generally a 400-meter oval track, usually found at a high school or college. Although there are many types of track surface, they are usually made of some sort of textured rubberized surface.
- Pros: A safe, relatively soft surface designed for running. You will not be hit by a car or attacked by a bear while running on the track. (If you are, it will be one hell of a story.) Because a track is a fixed distance, you can know exactly how much distance you’re covering. Four laps=one mile.
- Cons: It’s a 400-meter oval. If you’re going for distance, it can become a bit monotonous. Also, if you always go in the standard counterclockwise direction, it’s possible to develop discrepancies between your “inside” and “outside” legs, which could potentially lead to injuries (but this would take many laps of running on a track almost exclusively).
- Recommendations: If you have access to a local track, incorporate it into your routine at least once a week. Tracks are a great place to practice running intervals. Interval training will break the monotony of just running lap after lap endlessly, and will absolutely help you become a better runner because you’ll be running faster than usual and developing a great sense of pacing.
Description: You know what grass is.
- Pros: Very soft surface. Easy on the legs. It’s just fun to run on grass—makes you feel like a kid. Sports fields can be a great place to run intervals or “strides”.
- Cons: Not many. Allergies? Some grass surfaces could be a bit uneven–watch for “potholes” or other hidden obstacles. It might be hard to find a grass surface large enough to run distance on.
- Recommendations: One of my college cross-country teammates liked to say: “Want to run [uninjured] until your senior year? Run on grass.” Sage words. Thinking of incorporating some barefoot running? Choose this surface, and build up slowly. Many top track teams practice barefoot running on grass–it builds strong feet and ankles, and often running barefoot on a soft surface “automatically” improves running mechanics because the foot interacts more efficiently with the ground because of the thousands of proprioceptive nerves located in the foot.
In reality, many runs may make up a blend of these surfaces depending on our routes, but I hope this list helps you make the best decisions about where your feet lead you.