Science of Running

On Saturday 26th March 2016, Becca, and Zoë ran the IAAF World Half Marathon in Cardiff!

In our preparation to run 13.1 miles we looked into the science behind running. How important is running to humans? How do we run? And the question most people think: WHY do people run nowadays?

How important is running to humans?

Becky running the Cardiff Half Marathon in October 2015!

Becky running the Cardiff Half Marathon in October 2015!

Tens of thousands of years ago when we were living in caves and battling mammoths and bears for our food, we needed to be able to run to stop ourselves from becoming food! Prehistoric humans would travel for miles every day searching for food and shelter and would be very physically strong and fit. In modern society we don’t need to hunt for our food, we go to the supermarket. We have public transport and cars to take us places, and we are the top predators in most societies. Our need for running has decreased so much that most people only run to catch the last bus home. Running is now a sport and a form of recreation.

How do humans run?

Running uses a lot of different muscles as your legs move you forwards, for example your quadriceps (thigh muscle) extends your leg forwards and keeps your knee stable, and your calf muscle lifts your leg off the ground. Running is physically different than walking. When you walk you always have one foot on the ground, but when you run you are pushing your body off the floor so both feet are off the ground with every spring step forwards.

Becca after finishing her first 5K race in May 2015!

Becca after finishing her first 5K race in May 2015!

Forces play and important role in our ability to run. There is gravity pulling us to the floor, our muscles working to push us forwards, and drag from the air slows us down. Isaac Newton’s third law of motion is at play too: for every action there is an equal and opposite reaction. When your foot strikes the floor you are exerting a downwards force on the ground, but an equal amount of upwards force is going from the floor into your leg. You can get injuries such as runner’s knee and shin splints from too much force from the ground so you need to make sure you have good running technique to protect your joints.

Sweating to cool off and your body using water and nutrient stores to keep your body going can leave you dehydrated and in need of nourishment. You need to replenish these supplies by drinking plenty of water and eating a healthy snack after a run. A mix of protein and carbohydrate is best, such as some nuts and a banana, or boiled egg and toast. The carbohydrate tops up your energy stores and the protein supports muscle repair. You need to rest between runs, especially if you are a new runner as your muscles need to get used to this new movement! Muscles actually tear slightly when you exercise and they need time to rebuild, making them stronger and improving your ability.

Why do humans run nowadays?

Runners have lots of different reasons for running. For some it is a relaxing way to end the day, for others it is to manage weight, and many run for competitive reasons. Exercise is a well documented effective treatment for mental illnesses such as depression. Exercising releases endorphins, which are natural chemicals in your body, that make you feel calm and positive. This is often referred to as “runner’s high”.

Whether you want to be the first across the finish line, or be able to catch your bus home, running is something that humans are designed to do!


Zoë and Becca completed the half marathon and were really pleased with their times! They raised a lot of money for their chosen charities. Zoë ran for Coalition to Cure Calpain 3, and Becca ran for Mind.

Posted in Biology, News, Physics
Related pages