Reasons to run
Regular exercise such as running keeps you happy and healthy, inside and out. But why is it so good for you? Here are some of the benefits of running and the science behind how it improves the way your body works.
Increases the flow of blood and oxygen around your body
What happens?
When you run, your heart rate (the number of times your heart beats per minute) and stroke volume (the amount of blood your heart pumps out with each beat) increase, improving the flow of blood around your body. Because your blood carries oxygen, this helps supply your muscles with the oxygen they need during exercise.
How does this help me?
The amount of blood and oxygen your heart pumps out every minute is called your cardiac output (CO). Your CO will increase with training, so every heartbeat will supply your body with more oxygen than before.
A higher CO means you’ll be able work harder to improve your performance during training runs, but it will feel like the same amount of effort as before your CO increased. For example, if running a mile in 10 minutes takes your heart rate up to 160 bpm (beats per minute), after a few weeks of training you’ll be able to do the same run with your heart rate peaking at 140bpm.
Similarly, when you’re resting, your heart rate will drop because your body will be working more efficiently.
Your muscles absorb more oxygen from your blood
What happens?
Exercise triggers the growth of capillaries (tiny blood vessels) in your muscles. A regular runner will have an average of five to seven capillaries per muscle fibre, while a non-runner will only have three to four.
How does this help me?
Capillaries let water, oxygen, carbon dioxide, nutrients and waste products pass between your blood and muscles. Having more capillaries means your muscles can get more oxygen and nutrients – and easily offload waste products and gases – when you exercise.
The maximum rate at which your muscles can take oxygen from your bloodstream is known as your VO2 max. Although your sex, age and genetics affect your VO2 max, it will increase when you run regularly.