Runners are often creatures of habit, sticking to the same pace on the same routes and surfaces as they become comfortable and familiar. But one of the best things you can do for your running is to add in some variety.
Changing the surface you typically run on — whether it’s road, trail or treadmill — can actually make you more resilient. Here’s what you should know about choosing a surface and how to safely switch it up.
The Gait Cycle & Surface Impact
Each surface you run on impacts your body in a unique way. To understand how you adapt to different surfaces, it helps to have basic knowledge of the running gait cycle. This cycle consists of two major components: the stance phase and the swing phase. Your foot is in contact with the ground during the stance phase (about 40% of the time when you’re running), and the swing phase is when your leg is in the air before you make contact (about 60% of the time).
During the stance phase, your muscles and tendons act like a spring. They both absorb and release energy. Your shoes and the surface you run on also play a role in this. Harder surfaces (like asphalt or concrete) act like a stiffer spring than a softer surface, such as grass.
Our bodies like to maintain equilibrium. So even though it may sound counterintuitive, your legs need to be less stiff in response to a surface that is hard, and stiffer to compensate for a softer surface. Your body compensates for how hard or soft different surfaces are. Amazingly, your body can adjust on the fly to the variety of surfaces you are landing on.
AdventHealth physical therapist Allison Burnham helps explain: “Running on different surfaces leads to changes in ‘leg stiffness,’ or how much your muscles are contracting. If you run on a softer surface, your leg tends to be stiffer and you may be at increased risk for bone injuries such as stress fracture. When you run on a harder surface such as asphalt, your leg tends to be less stiff and you could be at increased injury for soft tissue injuries.”
Why is all this important? Because it helps explain why there is no “perfect” surface for running — only pros and cons to weigh for individual runs and workouts. Your body can adapt well, but since running is already a repetitious sport, switching up the surface you run on will help teach your body to adapt and stay healthy.
Pros and Cons of Running Surfaces
Concrete
• Pros: Concrete sidewalks are easily accessible for just about everyone. They present little hazard for tripping (as long as they are well-maintained) and are a smooth surface for faster running.
• Cons: Concrete is the hardest surface to run on and very high-impact. It also tends to be monotonous with little variation.
Asphalt
• Pros: Asphalt is slightly “softer” than concrete and equally smooth and accessible. It’s where most runners log the majority of their miles! It’s ideal for fast, efficient running.
• Cons: Asphalt is also high-impact with minimal variety, just like concrete. Beware of roads that are significantly cambered as they can stress your legs and hips.
Treadmills
• Pros: Treadmills are the ultimate in safety and allow busy individuals to multitask with kids at home or stay safe in difficult conditions. They can help you learn to hold a consistent pace for moderate efforts.
• Cons: While treadmills vary in “softness” with different quality machines and various manufacturers, they are the ultimate in monotony for your joints. They also tend to alter your gait from what you would do naturally outside.
Track
• Pros: Tracks are a fast, responsive surface for hard workouts with less impact than concrete or asphalt.
• Cons: While ideal for speedy, short workouts, tracks are not a great option for long runs, both for monotony and for the continuous turns that can cause imbalances.
Sand
• Pros: Sand can vary depending on how close or far you are from the water, but it is a soft, forgiving surface that can provide a tough workout and build foot and ankle strength.
• Cons: Sand is not recommended for long or fast efforts. Start short and slow to avoid placing too much stress on your ankles, Achilles and shins, as they can get overworked quickly here.
Grass and Smooth Trails (Packed Gravel or Dirt)
• Pros: Grass and smooth trails are softer and provide more variability than asphalt or concrete to help build foot and ankle strength. Paths around parks are an ideal way to get off the road without having to navigate more challenging terrain.
• Cons: Your legs will work harder to run faster on this surface, and getting comfortable running fast on trails can take some time. Rain can make these surfaces muddy and slick, so use caution during inclement weather.
Technical Trails (rocky, root-covered, etc.)
• Pros: This is the ultimate in variety as your feet rarely land the same way twice. With practice, you’ll learn to be nimble and athletic and build a strong lower body from the feet upwards.
• Cons: Roots and rocks and hills, oh my! Technical trails take practice and can be slow going as you learn to navigate the terrain. Take care not to trip or turn an ankle.
While there are no large-scale studies on different running surfaces and injury rates, most coaches agree that varying the surfaces you run on is best for your body. If you’re training for a race on a specific surface, make sure to spend quality training time on that surface so your body can adapt before race day.
For personalized guidance on how to safely optimize your fitness, expert care recovering from an injury or help to prevent one, reach out to the team at AdventHealth Sports Med & Rehab.
