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Cadence

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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=
So what should your cadence be? It's generally commonly accepted that a turnover of 90 stepsstrides/minute is optimum best for most people (180 steps/minute if counting both feet). This appears to be a "goldilocks" cadence, but all runners will change their cadence with their running speed. To start offchange speed, check your a runner can change their cadence when you are running and if the number is 90 /or highertheir stride length. In practice, runners will change both cadence and stride length, pat yourself on the backincreasing both to go faster and reducing both to go slower. If So, it seems that the number is lower than 90 then you should look at changing your SPM cadenceis a reasonable target for a runner's comfortable pace on level ground. Your A cadence does not have to below 85 SPM is probably too low unless a runner is going unusually slow, almost jogging in place. Cadences above 95 SPM will be exactly 90, and when a runner is likely to change somewhat with your picking up the pace and terrain, such as interval training. A faster pace may have runner should avoid cadences over 95 SPM in typical training, as the stride can become inefficient. Cadence is a goldilocks zone, and higher cadenceis not better. Extremely high cadences are sometimes seen going fast, as will up or down hill sections. steep, technical ground, where rates of over 140 SPM (280 steps/minute) can happen!
=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 Strike]], and more. The accuracy of these approaches is covered in my [[Comparison of Cadence Monitors]].
* 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="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>