Why you should not run on concrete?

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Of all the places to run in the United States, sidewalks are the most common. Depending on where you live, these suburban jackpots stretch for miles in any given direction—attracting all sorts of outdoor enthusiasts. Coincidentally, it’s some of these same people that complain about “bad knees” or “achy joints.”

What gives? Running is supposed to be a physically and emotionally beneficial outlet. Are runners being divinely punished for listening to the health gurus and logging those miles? Not necessarily. There are many variables that can lead to aches and pains; that’s true for any athlete.

One variable to consider: Running on the sidewalk every day probably isn’t helping. In fact, running on the same surface over and over (even the soft ones) isn’t doing your body any favors.

Whether you’re injury prone or merely cautious, knowing the differences between running surfaces is important for a runner. Each surface certainly has its pros and cons. From injury-inducing to running on clouds, here’s what you need to know about where your feet are going.

Concrete and Asphalt

Those concrete sidewalks are some of the hardest surfaces you can run on—followed closely by asphalt. The sheer (repeated) force at which your feet strike concrete or asphalt can cause shin splints and stress fractures. 

On the flipside: The consistency of these surfaces makes it easier to stabilize and decreases the risk of falling. And if you’re training for a road race, it is helpful to train on asphalt to prepare for racing conditions. 

Some quick road running safety tips: Pick roads with spacious shoulders and bike lanes or sidewalks that allow for more space between you and cars passing by. When running in the dark, remember to wear a headlamp and have a flashing light on your backside so that you are easily seen. And don’t forget to yield to all stop lights, crosswalks, and major roads.

RELATED: A Trail Runner’s Survival Guide to Running Roads

Treadmill

While it’s not as firm as concrete, the treadmill is still considered a hard surface. It’s important to understand that running on a treadmill is just different from running without being propelled. Your stride length is different, your pace will be different, and you’re actually using different muscles. Outside, you are pulling yourself forward. On a treadmill you are using less of your hamstrings and more of your quads which can actually change your running gait.

A study published in the Journal of Sports Physiology and Performance found that treadmills have an average shock absorption rate of 71 percent compared to 0 percent on asphalt. This “leads to a reduction in energy returned to the athlete, which in turn increases physiological stress and rating of perceived exertion during endurance running,” the researchers concluded. 

Other things can alter shock absorption (ultra cushioned shoes, body mechanics, to name a couple), but running surface also plays a role in how much force your body absorbs every time your foot lands. That force can be anywhere from two to five times your body weight. 

Treadmills are great training tools and a good way to mix up your training, but logging a lot or all of your miles on the treadmill has the potential to mess up your IT band cause other injuries. It can also make it harder to transition back to your regular running gait if you’re planning to run a road or trail race. 

But still, the benefits of treadmill running are clear: It’s a great time saver and resource in inclement weather­. Attempting to run your mileage too fast or doing so in bad weather can both cause illness and injury.

RELATED:Break Up Boredom With This Treadmill Hill Workout

Sand

Running on sand is one of those things that is much less glamorous than it looks. It takes a lot more effort to run on sand because the surface is not stable. A runner is constantly stabilizing and balancing, which will make you stronger in the long run.  

On the upside, running on a beach is a very efficient cardiovascular workout, the surface is soft on joints, and you can take a dip in the water after the run. Despite the beauty though, running on the sand can be brutal on ankles, shins, and knees.

Experts recommend wearing a good pair of running shoes for long runs. Barefoot beach running should be kept to under a mile to avoid injury. 

Trails

Dirt, gravel, and grass are perhaps the most natural running surfaces. But that hardly means it’s without risk. Trail running requires constant, heightened attention. One misstep can result in a broken bone or a life-threatening fall. Every trail offers unique challenges, but most will provide their fair share of tree roots, divots, rocks, and ledges. 

The risk doesn’t come without reward though. Trail running has significantly less impact on your bones and joints than running on concrete or asphalt. The natural terrain is also a great asset to overall strength and agility.

But trails don’t necessarily have to be in treacherous, forested areas that you have to drive far to reach. Dirt trails in your neighborhood open space or along a greenbelt can also give your joints the break that they need without as many hazards.

There’s no perfect running surface, so deciding where to run really just comes down to personal preference. Are you recovering from ankle surgery? Stick to the flat, firm surfaces. Do you live in a state that’s snowy and slippery? Opt for the treadmill during times of harsh weather. Ultimately, the best choice is to vary the surfaces you’re running on as much as your body allows. The more you mix it up, the better your legs learn to adapt and the stronger they will become. That means less aching and more running. Who doesn’t want that?

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