by Dawn P. Coe, University of Tennessee and Elizabeth (Kip) Webster, University of Tennessee, [This article first appeared in The Conversation, republished with permission]

Curious Kids is a series for children of all ages. If you have a question you’d like an expert to answer, send it to curiouskidsus@theconversation.com.

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Why are some people faster than others? – Jon, age 14, Macon, Georgia

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Usain Bolt, the world’s fastest person, ran a 100-meter sprint at a speed of 23.35 miles per hour (37.57 kilometers per hour).

That’s mind-blowingly fast for a human. It’s about the same speed as cruising in a car through your neighborhood or in a school zone. It might not seem that fast when you’re in the car, but for a person? Few runners in the world can even come close.

There are several reasons why some people can run very fast while others tend to run more slowly. Genetics – the traits you inherit from your parents – play a role, but so do your choices and experiences.

As pediatric exercise scientists, we create and evaluate programs that help children be healthy. The exciting news is that while you have no control over your genetics, you can train to improve your speed.

Fast twitch, slow twitch

One major factor that influences your ability to run fast is the structure of your body, including how your muscles work.

The human body has more than 600 muscles that work together, allowing you to move in different directions and at various speeds. These muscles are made up of groups of fibers. There are two main types: fast twitch and slow twitch.

Muscles have different mixes of these fiber types. For example, two muscles make up the calf: One is predominantly fast twitch – that’s the gastrocnemius, used for sprinting and jumping. The other is mostly slow twitch – that’s the soleus, used for walking and jogging.

Fast-twitch muscle fibers are larger and help your body move quickly and generate significant force. Sprinters tend to have an abundance of fast-twitch muscle fibers. However, this muscle fiber type also tires quickly, which limits how long you can run at top speed to relatively short distances.

Slow-twitch muscle fibers are smaller and help you run at slower speeds, but with greater endurance. Long-distance runners and competitive cyclists tend to have a lot of these muscles.

How much you have of each type of muscle fiber – fast twitch and slow twitch – is mostly determined by your genes, so you’ll have to work with what you’re born with when it comes to muscle types. But exercises can help train those muscles.

Your brain plays a big role

Physical ability isn’t just about muscle. Your brain plays an important role, too.

Your skeletal muscles are controlled by your brain – you think about your actions and then execute the movements. For example, you can control how long your stride is, how your arms move, how your feet hit the ground and even the techniques you use to breathe.

You can teach your body to use the best running techniques. That includes proper posture, so your body is standing tall, and an economical stride, so your feet land below you rather than too far out in front, where they can slow you down.

Five tips for running faster, from an Olympic sprinting coach.

You can also improve your running form by using your whole body, with your arms pumping in opposition to the legs, running on your toes and maximizing the time spent in flight phase with both feet off the ground. Using proper running techniques helps the muscles create more force and work together, which helps you run faster.

The more you practice an activity, the better you will get. As your ability to run fast increases, challenge yourself to run even faster.

How to train to run faster – myth-busting!

You may have heard your friends chatting about ways to boost your speed or searched the internet for tips on getting faster. Time to bust some of those myths.

Myth 1: You have to run as fast as you can to train to be faster. That’s false!

You don’t have to run as fast as you can to get faster, and it actually helps to take short breaks to recover in between activities where you are sprinting.

Myth 2: You need to lift heavy weights to get faster. False!

Functional strength training involves performing exercises that help you get better at specific movements. They involve using either medium weights or just the resistance of your own body weight. Doing planks, lunges, step-ups or jump squats are great examples. These activities focus on the muscles that are instrumental during running.

Myth 3: You need to specialize in running early in life to become a fast runner. False!

Picking one activity to focus on early in life may actually limit your ability to develop into a fast runner. Doing a variety of physical activities can help you develop new skills that improve your running. For example, the movements and endurance used in soccer may translate into the ability to run faster.

Myth 4: Training isn’t fun. False!

Training programs can take many shapes and forms. You can play running games with your friends, work on fast footwork using an agility ladder or create obstacle courses. There’s nothing like a little healthy competition to motivate your training.

What’s important is having fun while training and participating in activities that promote running speed on a regular basis.

So, whether you want to be the next Usain Bolt or you just want to win a race against your friend, remember that with a little bit of genetic luck and hard work, it may just be possible.

Dawn P. Coe, Associate Professor of Exercise Science, University of Tennessee and Elizabeth (Kip) Webster, Associate Professor of Exercise Science, University of Tennessee

This article is republished from The Conversation under a Creative Commons license. Read the original article.