Are you a bounder?

• Posted onliz
• in Masters Article Library, Running, Uncategorized
• onMarch 25, 2016
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Why is your cadence important in running?

When it comes to cadence or stride rate, whether purists like it or not, there is a magic number. This comes from the often mis-quoted evidence of author and world class coach Jack Daniels. Daniels observed that the elite runners in his sample group ran at a cadence of “180 steps or more per minute”.   Thus developed a myth that everyone should run at exactly 180 spm (strides per minute). This is not strictly true – each individual is different and will have their optimal cadence at a given pace and many elite runners race at stride rates closer to 200 spm! But, the reason that this magic number is so useful and sought after, is that it is a key indicator in assessing the efficiency of a runner.

There are two reasons why cadence has an impact on efficiency:

1. Elastic recoil. A runner whose cadence is lower than 180 spm say 150-160 spm (when running at a pace that is more than conversational) is very often a runner that is over-striding. Over-striding generally results in the runner spending too much time on the ground with each stride. And as discussed in the blog post How to Run on Springs , if our landing foot spends too much time loading the stretch on the ground then we cannot make use of elastic recoil and the energy from the stretch shortening cycle to assist in our propulsion.
2. Injury prevention. A runner whose cadence is 150-160 spm is often bounding with long strides and greater vertical displacement than a 180 spm runner.   A greater vertical displacement will result in more force through the joints on every stride. Furthermore, an over-striding runner will tend to reach out with the lead leg, and often land on their heels. The runner will effectively be putting on the brakes with every stride. The heel is not designed to take impact shocks and this, in itself, can lead to injuries. Encouraging a runner to increase their cadence can be helpful in correcting an over-striding runner.

How to check your cadence

On a flat running surface, start your watch and count your right foot strikes for 15 s. Repeat this 3 or 4 times and take an average count. Now multiply your strike count by 4 and then by 2 so that you get the strides of both legs in a minute. Eg. 22 right foot strikes in 15 s is 176 spm.

Make changes slowly

Changes to your cadence (from say 160 to +180 spm) will require changes to the way you are running – and this is a good thing. But, as always, changes need to be made carefully. Aim for a 5% change at a time – wait until you are comfortable and the increased cadence becomes your default cadence before increasing your cadence further.