Why runners get injured

Every other article on this site is about one problem in one place. This one is about the thing they have in common, and if you only read one, read this.

How often it happens

A novice gets hurt at more than twice the rate of someone with a few years behind them. Same bodies, same roads, same shoes.

What the experienced runner has is not better tissue. It is a feel for how quickly things can change, usually acquired by getting it wrong a few times.

The gap, not the amount

Tissues adapt to what you ask of them. Bone gets denser, tendon gets stiffer, muscle gets stronger. All of that happens slowly, over weeks and months.

Training changes faster than that. You sign up for a race, the plan steps up, and the step arrives in one week while the adaptation takes six.

Somebody running 80 km a week is not at higher risk than somebody running 30, as long as they got to 80 gradually and their body has had time to meet it. The risk sits in the change, not in the number.

Where the confidence runs out

Here is the part most articles on this subject skip.

So the field agrees that training error is where injuries come from, and the systematic review says we cannot tell you which error.

I find that genuinely useful rather than discouraging. It means anyone handing you a rule with a number in it is going beyond the evidence, and it explains why two runners doing the same thing get different outcomes.

The two sides you can actually change

If the gap between demand and capacity is what matters, then there are two directions to work in and both are available to you.

Lower the demand, temporarily, when something is sore. That is not resting. It is editing: which runs stay, which get shorter, which surfaces and gradients come out. Most of what we do in the first fortnight of an injury is this.

Raise the capacity, permanently. Strength training had the strongest injury prevention effect in the meta-analysis of exercise interventions, with overuse injuries roughly halved, while stretching showed no effect at all³. Our article on strength training has the detail.

The distinction between what you did and what it cost you is the useful frame here. External load is the kilometres and the pace; internal load is what those cost your particular body on that particular day⁴. Training plans are written in the first and injuries happen in the second.

What else feeds into it

Load is the biggest lever and it is not the only one.

Previous injury is consistently one of the strongest predictors of the next one, which is an argument for finishing rehab properly rather than stopping when the pain does.

Sleep, energy intake and stress all sit on the capacity side. A body that is under-slept and under-fuelled has a lower ceiling, and the same training week lands differently. Our articles on sleep and under-fuelling cover those.

Running technique matters less than the internet suggests and more than nothing. It is a tool for specific problems rather than a general upgrade, which is the argument in our cadence article.

Which injuries, and where

The knee is the most common region, with pain around the kneecap the single most frequently reported problem in running injury studies⁵. After that the shin, the Achilles and calf, and the foot.

Our index by body region sorts them by where you can point, which narrows things faster than anything else you can do at home.

When to get help

The last one is the pattern people normalise. Three injuries in a year is not bad luck, and it usually has one cause underneath it.