3 ways running helps your heart get stronger

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‘For any running other than sprinting, the muscles depend on the constant supply of oxygen as fuel,’ says Clodagh Dugdale, a sports physician at Fit Again Sports Therapy. ‘The heart is the pump that pushes oxygenated blood around the body, transferring it to muscles in exchange for carbon dioxide and then transporting this oxygen-depleted blood back to the heart and lungs.

The amount of blood your heart can push out in one minute (cardiac output) is the product of the amount it can push out in one beat (stroke volume) and the number of beats per minute (heart rate). Over time, regular training can increase this output by up to six times due to the left ventricle growing stronger.’ Most people need their heart to beat at about 70 beats per minute (bpm) at rest in order to pump enough blood round the body. For highly trained athletes, this figure can drop to as low as 40bpm, thanks to the strengthening adaptations of the heart.

What happens to your heart when you run?

1. The heart increases in size as a result of muscle development on both the right and left sides; therefore, there is more muscle to provide a greater force of contraction and push out more blood.

2. The aortic valve on the left ventricle, the cavity from which oxygenated blood is pushed out, also grows and widens in diameter, significantly increasing stroke volume.

3. The heart undergoes increased capillarisation (increase in size and number of capillaries), delivering a greater blood and oxygen supply around the body during a run.