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How does the surface of the ground affect a runner's speed?
Question Date: 2017-10-25
Answer 1:

Let's think first about what happens when we are standing (not running) on hard surface, like concrete for example. When we are standing, gravity is pushing down on us (because we have mass) and the concrete is pushing back on us through our feet...right? Don't believe me? Stand up and try it! It works!

Okay now let's start moving, but not running just yet. What happens when you jump? You use your leg muscles to push on the ground, and the ground pushes back to propel you towards the sky! The amount that the ground pushes back depends on the material that the ground is made of and how that material is organized.

How does this affect us when we run? Well if you tried to run on a very thick block of concrete, like a sidewalk for example, you wouldn't have to think twice about running because the force with which the concrete pushes back is equal to how hard you are hitting the ground while you run. If you tried running on a very thin block of concrete though--let's say as thin as a popsicle stick--then you would have to worry, because that amount of concrete probably won't push back on you! Instead, it will crumble under the force of your feet and you'll just fall right through it!

The concept is similar for other materials. If you can, try running on sand, concrete, and then the track at your school and compare how each of them feels. Here's what I can tell you about each of these experiences, but you should seriously try it for yourself:

1) Dry sand usually slides around when you try to run on it--so it's taking away some of the force that your feet are putting into the ground--and it feels like you're going nowhere even though you're running really hard!

2) Concrete doesn't slide around, but it also doesn't change it's shape when you run on it--so running on it feels pretty normal!

3) If your school has a track covered in special rubbery plastic called polyurethane, then when you run on it you might feel a little faster! This is because the material is a little bit "bouncy", so it pushes back on your feet with even more energy than what you put into it with your feet.

So this is what I hope you learned from this: the surface of the ground affects a runner's speed because the material and structure of the surface influences how much force the ground pushes back on their feet with.

Change the material and structure of the ground and you can either decrease (e.g. sand) or increase (e.g. rubber) the runner's speed! Some companies like Adidas (see Adidas Springblade) have even tried to change the material and structure of their shoes to increase runner's speed.

Hope this helps!

Answer 2:

I am sure that depends on the runner. There is no hard and fast rule. Maybe you should do some experiments to find out! You can put on running shoes, and time yourself running over grass, dirt, pavement, mud, etc. Then tell me!

Answer 3:

By asking google a bout your question, I got a lot of answers. It's an interesting question, and here are some of those answers:

1. If your feet grip the surface better, you can run faster.
2. Soft surfaces - like sand! - can slow you down a lot.
3. You and your joints are more likely to get injured when running on some surfaces, as compared with others.

Visit the following links: surface and running

This link is from 'Girls Gone Sporty':
surfaces and your performance

Here's a link with an experiment to test different surfaces, but its video is loading too slowly:
surface affect running

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