Training Load and Cadence: The Real Cause of Most Running Injuries
By Toby Sullivan, MCSP - Chartered Physiotherapist
When someone comes in with a running injury, the first question is usually "what's wrong with my technique?" It's rarely the right question to start with. In most cases, the running itself isn't the problem - how much of it, how quickly it's increased, and what's supporting it outside of running are what actually matter.
It's a load problem before it's a technique problem
Tendons, bones and muscles all adapt to running, but they need time to do it. Most of the running injuries I see - Achilles pain, shin splints, runner's knee - come from load going up faster than the body can adapt to it. That's a new training plan followed too aggressively, a jump in weekly mileage, or going from occasional runs to marathon training without much of a base first. The injury isn't bad luck. It's usually a fairly predictable result of the numbers.
Where cadence fits in
Cadence is how many steps you take per minute. It's not something that needs fixing for its own sake, and there's no single "correct" number everyone should aim for - but a very low cadence, often paired with overstriding, tends to increase the load going through the knee and shin with every step. For some injuries, a small, gradual increase in cadence is one of the more useful adjustments available, without needing to overhaul someone's entire running style.
The gap that's easy to miss: strength
A training plan on its own doesn't tell the whole story. A lot of running injuries come down to a strength and conditioning gap that hasn't kept pace with the mileage - the muscles supporting the joints simply aren't strong enough for the volume of running being asked of them. This is one of the most common things I check for, and one of the easiest to actually do something about.
How this gets assessed properly
Rather than watching someone run on a treadmill, which tells you relatively little on its own, I focus on the training itself - the plan, the mileage, the cadence - alongside proper strength testing. That includes isometric strength testing similar to the methods used in sports science, and jump testing to check power and any difference between your left and right side. Between the training picture and the strength numbers, it's usually clear what's actually driving the injury.
What this means practically
If you're dealing with a running injury, it's worth looking honestly at three things before anything else: how quickly your mileage has gone up recently, whether your strength training has kept pace with your running, and whether there's an obvious spike in your training around when the pain started. Often, the answer is sitting in your training log already.