Why do runners get so many injuries? And does strength training really make a difference?

Shengpengpeng Cai/Unsplash For many of us, running is one of the most accessible forms of exercise.

It’s free and you don’t need equipment.

But it is also one of the more likely to lead to injury.

Studies of novice runners report around 18 injuries per 1,000 hours of running , which is more than double the rate experienced by more advanced runners.

Most injuries seem to occur to the knee, ankle and lower leg, and are more likely to be “overuse” injuries, rather than acute muscle sprains.

Read more: My shins hurt after running.

Could it be shin splints? Overuse injuries tend to occur when a tissue is repeatedly loaded more than it can tolerate, without enough time to adapt.

This might happen because running starts to feel easier before your body is actually ready to do more.

So, what’s going on? And does improving strength alongside fitness help prevent injuries? Fitness increases faster than muscle and bones adapt When you start running, your cardiovascular system adapts quite fast.

Blood volume increases within days , your cells’ mitochondria (which generate energy for exercise) can adapt in as little as two weeks , and the number of blood vessels in your muscle increases in around four weeks .

As a result, aerobic fitness measurably improves within as little as two weeks, and runs that felt hard in week one can feel manageable by week four.

This can make it very tempting to go further and faster.

However, tendons and bones adapt on different scales and different timelines.

Tendon adaptations, such as becoming stiffer and stronger, typically take at least 12 weeks of consistent (and fairly heavy) loading.