This week I’ve been working on a YouTube video about something I never used to think about: the surface I run on.
When I was younger, it didn’t matter. Road, sidewalk, trail—I just ran. My body handled it. Recovery wasn’t something I thought about. Now I notice it. The surface I run on affects how I feel the next day. It affects how long I can stay consistent. It affects whether something small turns into something bigger.
Most of us race on the roads. That means you need to spend time on the roads. If you’re running a trail race, train on trails. If you’re doing a treadmill race, which now exists, practice on a treadmill.
But during the week, when you have a choice, the surface matters.
The main options are simple: trail, asphalt, and concrete.
Trail is softer. It’s easier on the body. For me, it’s not always practical. The footing changes. The pace is harder to control. GPS can be unreliable. It’s great when you can use it, but it’s not always the answer.
Concrete is the opposite. It’s everywhere. Sidewalks are convenient. Easy to access. But it’s the hardest surface we run on.
Asphalt sits in the middle.
It sounds like a small difference, but it’s not. Asphalt has more give because of how it’s built. It’s a mix of aggregate held together with bitumen, which is flexible. That allows it to deform slightly under load and then return to shape. Concrete is different. It cures into a rigid slab. Once it sets, it doesn’t flex.
Concrete is roughly 5–10 times stiffer than asphalt. It doesn’t give. Asphalt does—just a little. Over time, that adds up.
I don’t think running on concrete is bad. But small differences, repeated over time, start to matter.
When your foot hits concrete, more of the force comes straight back into your body. On asphalt, a small amount is absorbed by the surface. It’s not dramatic, but over thousands of steps, it adds up.
That difference shows up over miles. Over weeks. Over years.
These days, I try to avoid sidewalks when I can. I’ll step off onto the road. It’s not always possible. But when it is, I take it.
Small decisions like that don’t show up in a single run. They show up over time.