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Cadence is a critical part of running, lowering the stress on ankles, knees, & feet, improving [[Running Economy]], reducing injury rates, and enhancing [[Running Form]]. Cadence is how often your feet touch the ground and it's easy to modify.
=Correct Cadence=
=Measuring Cadence=
The cheapest way is to measure your cadence is to simply count how many times your foot touches the ground in a minute. However, it's much easier to use a [[Best Running Watch| running watch]] that displays cadence. Some watches will use a small [[Footpod]] attached to your shoe, but others make use of an internal accelerometer. (There's also more advanced options, such as [[RunScribe]] which make Footpods that measure a wide range of biomechanical data in addition to pace and [[Cadence]], including Braking G's, Impact G's, Ground Contact Time, [[Foot strikeStrike]], and more.)==The accuracy of these approaches is covered in my [[Comparison of Cadence Monitors==]]. [[File:Cadence Comparison.jpg|none|thumb|1000px500px|A comparison of cadence monitoring devices during See my [[High Intensity Interval Training]].]]The graph above is from a [[High Intensity Interval Training]] session, which is a challenging test Comparison of Cadence monitors. The [[WarmupMonitors]] and [[Cooldown]] sections of the run are not included, just the intervals. You can see the cadence rise to above 100 during the fast, high intensity intervals, then drop back to my for more normal 90, then a further drop as I walk for a short period before commencing details on the next interval. I don't normally walk, but I wanted to challenge the cadence monitors a little extra. I avoided looking at any device during the run, as that can prevent the internal accelerometer based systems from operating without the normal arm swing. * I wore five watches, two accuracy of [[Footpod]]s and the Garmin HRM Run sensor for the run. * The blue line is from a [[Polar M400]] with the Polar Stride Sensor [[Footpod]]. The Stride Sensor is huge, but it seems to provide the best data. The Polar data is smoother (greater sampling frequency), and reflects the changes in Cadence a little better than other sources. For instance, I stood stationary for a few seconds around the 7:30 mark, and the Polar reflects this drop better. * The purple line is from a [[Garmin 920XT]] with a Garmin Footpod. This is very nearly as good as the Polar data, and matches the changes fairly accurately. * The green line is from a [[Garmin Epix]] with the Garmin HRM Run heart rate strap Best Running Watch| watches that also monitors measure cadence. This matches the Garmin Footpod nicely, showing a similar sampling frequency. * The red line is from a [[Garmin 225]] that is relying on its internal accelerometer. The Garmin 225 is firmly strapped onto my wrist to ensure its optical heart rate monitor is effective. This is rather tighter than I would like, and mostly it does okay. You can see it's a little delayed in some of its responsesll find more detail, and at the 5:00 and 6:30 minute marks it misses the rise completely. While it's far from perfect, it does a reasonable job. * The orange line is from an [[Suunto Ambit3]] using its internal accelerometer. The Ambit3 was reasonably firmly strapped to my arm, but nowhere near as tight such as the Garmin 225. I suspect it's this looseness that causes the poor data for the Ambit3. You can see that on the fast intervals the Ambit3 loses the plot completely and assumes that my cadence drops to zero. [[File:Cadence Comparison2.jpg|none|thumb|1000px|A comparison of cadence monitoring devices during a [[Long RunHigh Intensity Interval Training]]session.]]The graph above is the comparison of a [[Garmin 920XT]] with a [[Footpod]] (red line) with a [[Garmin 225]] using its internal accelerometer (blue line). You can see the internal sensor is far noisier, but worse, it has an overall bias. The Footpod showed an average cadence of 91.1 while the internal sensor was 89.3. That's not a huge difference, but it's far from ideal. I plan to perform further tests of the internal accelerometer based devices as time allows.
=Changing Cadence=
There are several ways of changing your cadence.
* Some [[Best Running Watch| running watches]] will display your cadence. The most common source for cadence is a [[Footpod]], but some Garmin watches can get cadence from the [[Heart Rate Monitor]] strap. The watches that provide cadence from an internal accelerometer tend to be less accurate than the other options, but it works if you make some allowances. The best watches will alert you if your cadence is out of the range you specify. See [[Best Running Watch]] for details on which watches have the functionality you want.
* You can [[Remixing Music For Running| remix music]] so that it is a higher tempo.
* If you run with a Smartphone, Spotify can detect your cadence and provide music with the right tempo. You can then adjust the tempo to match what you want your Cadence to be. I found the cadence detection to be pretty good and it's nice to have a wide selection of music that's the right tempo. Most of the time Spotify didn't seem to give me upbeat music, and I have better results with remixing music. Of course, the remix process is tedious and time consuming, so Spotify is much better than listening to music with the wrong beat. (This works on the free version of Spotify as well as the premium service, but only on the mobile app.)<br/>
{| class="wikitable"
|- valign="top"
|[[File:Spotify2.png|right|thumb|100px|Spotify detecting your cadence.]]
|[[File:Spotify1.png|right|thumb|100px|Spotify will allow you to adjust your target cadence in 5 BPM steps.]]
|}
* Having the correct [[Arm Position]] is important for maintaining your cadence. If your arms are too low it will be quite difficult to keep your cadence high.
* Lighter shoes tend to raise running cadence, probably due to the extra effort required to move a heavy shoe backwards and forwards.
=The adaptation processAdaptation Process=
To start off, the change in cadence will feel very strange. I remember adjusting my cadence, and felt like my shoes were tied together! My steps were so short and fast that things felt all wrong. It took several weeks to adjust, but when the adjustment did take place, my running improved dramatically. I credit cadence as a key part of my success in going from a 4+ hour marathon to sub-3 hour and is one of my [[Running Breakthroughs]].
=The Science of Running Cadence=
* A higher cadence also reduces peak leg deceleration as well as peak impact forces in the ankle and knee joints<ref name="Clarke-1985"/>.
* Higher cadence is also related to a reduction in [[Overstriding]]<ref name="Heiderscheit-2011"/>.
* A cadence of around 90 is also associated with greater running efficiency [[Running Economy]] than lower or higher cadences<ref name="Hamill-1995"/>, though another study found 85 was optimal<ref name="LiebermanWarrener2015"/>. One problem with these studies is that they allow little or no time for the runner to adapt to the tested cadence, and I think this makes it probable that the detected Running Economy is not representative.
* Not surprisingly, a higher cadence reduces [[Delayed Onset Muscle Soreness]] and the associated weakness<ref name="RowlandsEston2001"/>.
* One study<ref name="WILLSON"/> showed that as people become tired, their cadence goes up, and with the higher cadence goes lower impact forces. Although a shorter stride/faster cadence results in less landing force, a longer stride length/lower cadence is associated with less of the impact force reaching the head<ref name="Mercer-2003"/>.
* A review of the scientific studies showed consistently that an increased [[Cadence]] reduces shock at the hip, knee, and ankle, vertical oscillation, and ground contact time<ref name="SchubertKempf2013"/>.
* Barefoot running tends to have a higher cadence than shod<ref name="Divert-2005"/>.
* Leg Spring Stiffness increases with higher cadence<ref name="FarleyGonzález1996"/>.
* There is relatively little evidence concerning the height or leg length of athletes and their cadence.
** A study of 37 male senior elite triathletes indicated that height did not change Cadence, but taller athletes were faster and had longer stride lengths <ref name="Brisswalter-1996"/>.
** It's been observed that elite runners in a 5K have cadences of 95-100+<ref name="Treadlightly"/>, but those runners are moving at a much faster pace than most runners.
[[File:Cadence and Impact.jpg|none|thumb|500px|This chart<ref name="Mercer-2003"/> shows the impact forces for three different cadences at the same speed. The thick line shows the Preferred Strike Frequency (PSF) and Preferred Strike Length (PSL), which was a cadence of 84. The thin line has the runners with a 10% slower cadence of 76 and shows increased impact. The dotted line shows 10% faster cadence of 93 and a reduced impact force.]]
[[File:Cadence and VO2.jpg|none|thumb|500px|A chart showing the oxygen cost and heart rate for different cadences. (Cadence values in red added)<ref name="Hamill-1995"/>. The highest cadence levels had impaired [[Running Economy]] but it should be noted the runners had relatively little time to adapt to the different values.]]
=References=
<references>
<ref name="Brisswalter-1996">J. Brisswalter, P. Legros, M. Durand, Running economy, preferred step length correlated to body dimensions in elite middle distance runners., J Sports Med Phys Fitness, volume 36, issue 1, pages 7-15, Mar 1996, PMID [http://www.ncbi.nlm.nih.gov/pubmed/8699842 8699842]</ref>
<ref name="Cavanagh-1989">PR. Cavanagh, R. Kram, Stride length in distance running: velocity, body dimensions, and added mass effects., Med Sci Sports Exerc, volume 21, issue 4, pages 467-79, Aug 1989, PMID [http://www.ncbi.nlm.nih.gov/pubmed/2674599 2674599]</ref>
<ref name="LiebermanWarrener2015">D. E. Lieberman, A. G. Warrener, J. Wang, E. R. Castillo, Effects of stride frequency and foot position at landing on braking force, hip torque, impact peak force and the metabolic cost of running in humans, Journal of Experimental Biology, volume 218, issue 21, 2015, pages 3406–3414, ISSN [http://www.worldcat.org/issn/0022-0949 0022-0949], doi [http://dx.doi.org/10.1242/jeb.125500 10.1242/jeb.125500]</ref>
<ref name="FarleyGonzález1996">Claire T. Farley, Octavio González, Leg stiffness and stride frequency in human running, Journal of Biomechanics, volume 29, issue 2, 1996, pages 181–186, ISSN [http://www.worldcat.org/issn/00219290 00219290], doi [http://dx.doi.org/10.1016/0021-9290(95)00029-1 10.1016/0021-9290(95)00029-1]</ref>
<ref name="Treadlightly">"Do All Elites Run at a 180 Cadence: None of the 5K Finalists at the US Olympic Trials Did" http://www.treadlightlybook.com/2012/07/do-all-elites-run-at-180-cadence-none.html</ref>
</references>