Scientists Identified 3 Running Metrics Linked To Stress On Your Joints

If you run with a fitness watch, you probably have a pretty good idea of your average pace, heart rate, and maybe even your VO2 max. But scroll a little further through your workout summary, and you’ll likely find a few numbers you’ve never paid much attention to.

Cadence, vertical oscillation, ground contact time. They all tell you something about how you run, but what are you actually supposed to do with that information?

And if you’ve ever dealt with a nagging knee injury or sore Achilles tendon, you might have wondered how the way you run has something to do with it.

A new study offers some insight into which running metrics are worth watching and what they might tell us about the stress our bodies experience with every stride.

Which running metrics actually matter

In a new study published in Medicine & Science in Sports & Exercise, researchers wanted to see whether the measurements collected by everyday running wearables could tell us something useful about the forces placed on our bodies.

They recruited 55 healthy runners and had them run at different speeds on a specialized treadmill.

While participants ran, sensors worn on their chests and shoes tracked their running form. Researchers then compared those measurements with estimates of the forces experienced by two common trouble spots for runners: the Achilles tendon and the knee joint.

Essentially, they wanted to know which numbers on a running watch might offer the best clues about how much stress different parts of the body experience.

These three running metrics stood out

Researchers found that three measurements were particularly useful for understanding the forces placed on the knees and Achilles tendons:

• Cadence: How many steps you take per minute. Taking quicker, shorter steps generally increases your cadence, while longer strides tend to lower it.

• Vertical oscillation: How much your body bounces up and down as you run.

• Vertical ratio: How much you bounce compared to how far you move forward with each stride.

Of the three, cadence may be the easiest and most useful metric for everyday runners to track.

Most running watches can measure it fairly accurately, and you don’t need any fancy equipment to understand what it means. Other measurements, like how long your foot stays on the ground with each step, weren’t as closely associated with the forces researchers examined.

One important thing to remember is that the study didn’t follow runners to see who actually developed injuries. It looked at how running measurements relate to forces on the body, which can help us better understand running mechanics but can’t predict whether someone will get hurt.

How to use your running cadence to improve your form

So, what should you actually do with this information?

Start by checking your cadence after your next run. Most running watches display it as steps per minute, and you may already have months of data sitting in your fitness app. Take a look at how your cadence changes during easy runs compared to faster efforts. You might notice that you naturally take shorter, quicker steps when you pick up the pace.

If you tend to take particularly long strides, experimenting with slightly quicker, shorter steps at the same pace may be worth exploring. Previous research suggests that modest increases in cadence can sometimes reduce stress on the knees.

And if you’re regularly dealing with knee pain or Achilles discomfort, a physical therapist can help you figure out whether adjusting your running form would actually be beneficial.

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The takeaway

If you have a fitness watch, chances are you’re already collecting more running data than you know what to do with.

This study suggests that cadence is one measurement worth paying attention to, especially if you’re curious about your running form and how your body handles each stride. Start by checking your average cadence after your next few runs. Notice how it changes with your pace, and whether you tend to take longer or shorter steps.

There’s no need to chase a perfect number. Think of it as another way to get to know your running habits and make more informed decisions about your training.