It has been a long-held belief in the running community that harder running surfaces, like concrete, are linked to an increased risk of injury.
However, as new evidence emerges, it suggests that we may have it wrong.
As we delve into the latest science, we will unravel the intricate interplay between running surfaces, biomechanics, and the risk of injuries.
While it may be near impossible to entirely eliminate the risk of injuries, making informed choices about running surfaces and training strategies can significantly reduce the likelihood of experiencing common running injuries.
If it is indeed true that different running surfaces can have a positive or negative influence on running injury risk, then it is important that we adapt our training accordingly.
In this article, we’ll explore the different types of running surfaces and whether there is indeed a causal relationship between running-related injuries to help you make informed decisions to safeguard your running health and optimize your performance.
We will cover:
- The Theory Behind Running Surface And Injury
- What Is Leg Stiffness, And Why Does It Matter?
- What Does The Science Say?
- What Surface Should You Run On?
- 5 Ways to Avoid Getting Injured
- Final Thoughts
Let’s get into it!
The Theory Behind Running Surface Type and Injury
We know that there is a clear link between the volume of running and the incidence of running-related injuries. But what about the connection between running surfaces and injury risk?
From a physiological standpoint, this association makes perfect sense. When you take a step forward and land on your extended foot during a run, the impact force delivered to your foot and leg can be several times your own body weight.
The question then arises: where does this substantial force find its absorption point within your body? The answer largely depends on the nature of the running surface you’re on.
Consider the unforgiving rigidity of a hard surface like pavement.
On such surfaces, there’s little to no give when your foot strikes the ground. As a result, the entirety of the impact force is transmitted to your leg. Your muscles, tendons, ligaments, and bones must work tirelessly to dissipate this force.
In essence, they bear the brunt of this mechanical stress.
On the other hand, softer running surfaces, such as a dirt path, provide a certain degree of cushioning and give. When your foot makes contact with this type of terrain, the surface absorbs a portion of the impact force, thus lightening the load on your leg.
The result is a reduced need for your leg to absorb as much force as it would on a harder surface. This decrease in mechanical stress is one of the key distinctions between running on different surfaces and is pivotal to understanding injury risk.
But is it that simple?
What Is Leg Stiffness, And Why Does It Matter?
When you switch from running on a solid concrete path to a soft, grassy trail, you might not immediately notice the complexities happening within your body. But be assured, there is a lot happening behind the scenes.
As you transition from one surface to another, your body automatically fine-tunes its movements to adapt to the change, ensuring you maintain balance and your running speed.
The adaptation that occurs was measured in a study conducted by Daniel Ferris and his team. They observed the mechanics of surface-dependent running.
Participants maintained a constant speed while running on both a rigid and a compliant surface. They measured factors such as leg force, the time their foot spent on the ground, and the angle of their leg at initial ground contact for each trial.
Analyzing this data, they modeled the runners’ legs as simple springs. Their findings shed light on how runners instinctively adjust the stiffness of their legs when confronted with variations in surface density and give.
Leg stiffness decreases when running on solid surfaces and increases when running on more yielding ones. In other words, the stiffness of your legs serves as a compensatory mechanism for the ground’s firmness.
So, we know what the body does on different surfaces, but what relationship do these mechanisms have with injury? Let’s take a look below.
What does the science say?
If you’re hoping that the science is going to clear up any misunderstandings, you’re going to be disappointed.
One study associated high-impact loading rates with specific injuries, such as tibial stress fractures, a common ailment among runners.
Davis’ research indicates a connection between leg stiffness, impact, and stress on the tibia. Runners who have previously experienced tibial stress fractures tend to exhibit higher impact forces, stiffer legs, and increased forces along their shins.
If this is the case, should runners who have experienced tibial stress fractures run on hard surfaces in order to activate the body’s natural adaptation and reduce leg stiffness?
To muddy the waters more, other research by Benno Nigg at the University of Calgary suggests that runners with high-impact loading rates may experience slightly lower overall injury rates.
Far more research is needed in this area to clear up the apparent contradiction in these two studies. Is it possible that different injuries respond differently to leg stiffness and impact loading rates?
Are some injuries more likely with stiffer legs, and are some more likely with softer legs?
One thing to mention is that both of the studies above, although well thought out, are almost 20 years old.
In a recent study, researchers sought to understand how different surfaces, specifically grass, synthetic track, and concrete, impact the accelerations experienced by a runner’s foot when it strikes the ground.
They were asked to run at the same speed on the three surfaces while wearing their own shoes, and an accelerometer was placed on their sacrum to measure the accelerations.
The results revealed that the type of surface had a statistically significant impact on the accelerations experienced by the runners.
Concrete, a commonly used running surface, led to higher mean acceleration (MA) and mean peak acceleration (PA) compared to the other surfaces.
This suggests that greater biomechanical loads are experienced on concrete, potentially increasing the risk of injury. Nevertheless, more research needs to be done.
What Surface Should You Run On?
As is clear above, there is no real scientific consensus regarding which surfaces we should or should not be running on.
Sometimes concrete may be good, and sometimes concrete may be bad, but the evidence isn’t concrete for either.
So, which running surfaces are suitable for you? The answer is simple: almost any of them.
Choose what brings you joy, whether it’s concrete, trails, or treadmills. Running in different environments can be an enjoyable experience, and, in reality, the specific surfaces you run on might not have a significant impact on your running journey.
I personally stick to trails as it’s what I enjoy most. But if I have a race coming up that involves concrete, I’ll include that in my training, too.
What’s more important when it comes to avoiding injury are the points below, so check them out.
5 Ways to Avoid Getting Injured
Now, there may be little to no clarity on which running surface you should or should not run on. But there are a few points in which the science is very clear.
Here are five ways to help avoid getting injured:
#1: Adopt A Gradual Training Approach
Imagine building a sturdy house – it takes time and careful planning. Similarly, your running journey should embrace patience and gradual progression. Resist the urge to rush into full-throttle training.
Instead, think of it as laying the foundation for a strong structure. Just like adding bricks one by one, incrementally increase your running speed, distance, and intensity over time.
This measured approach minimizes the risk of injuries and provides a solid basis for your running journey.
#2: Engage In Cross-Training
Incorporate diversity into your training routine. Engaging in multiple sports disciplines is not only fun but also essential for reducing the risk of sports-related injuries.
Repetitive movements from specializing in a single sport can strain developing tissues.
Cross-training with activities like cycling, swimming, or hitting the gym offers low-impact and varied workouts that support cardiovascular fitness without overloading vulnerable muscles.
Plus, cross-training is an excellent strategy for active recovery, promoting blood circulation and reducing the risk of injuries.
#3: Make Sure Strength Training Is Part Of Your Routine
Building lower extremity muscle strength is crucial in reducing running-related injuries.
High-intensity neuromuscular training, plyometrics, and balance exercises have proven effective for runners. A thoughtfully designed strength and conditioning program can enhance your body’s resilience, improve joint stability, and decrease the risk of injuries.
Start with comfortable weights and consider guidance from a qualified professional for tailored exercises.
#4: Get 7-9 Hours Of Quality Sleep
Sufficient sleep is a powerful tool for preventing injuries and avoiding overtraining.
Establish a consistent sleep schedule, create a sleep-friendly environment, and limit caffeine and screen time before bedtime to ensure 7 to 9 hours of quality sleep per night.
During sleep, the body undergoes vital processes such as muscle protein synthesis and growth hormone release, crucial for muscle repair and growth, which is especially relevant for runners during periods of high volume.
#5: Don’t Skip Your Warm Up
Warming up is an effective and accessible tool for injury prevention. It increases muscle temperature, enhances blood circulation, and activates the nervous system.
A comprehensive warm-up regimen has been shown to significantly reduce the likelihood of injury in adolescent runners. Incorporating warm-up routines before your runs can protect you from severe and overuse injuries.
Final thoughts
Scientific studies have provided some insights, but they also present paradoxes.
Despite these mixed findings, one thing is clear: more research is needed to unravel the complexity of the relationship between leg stiffness, impact loading rates, and running-related injuries.
In the meantime, train on the surfaces you enjoy, and if you make any big changes, whether it be training volume or type of surface, introduce them gradually.
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