Difference between revisions of "Cadence"

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So what should your cadence be? It's generally accepted that a turnover of 90 steps/minute is optimum for most people (180 steps/minute if counting both feet). To start off, check your cadence when you are running and if the number is 90 or higher, pat yourself on the back. If the number is lower than 90 then you should look at changing your cadence. Your cadence does not have to be exactly 90, and is likely to change somewhat with your pace and terrain. A faster pace may have a higher cadence, as will up or down hill sections.   
 
So what should your cadence be? It's generally accepted that a turnover of 90 steps/minute is optimum for most people (180 steps/minute if counting both feet). To start off, check your cadence when you are running and if the number is 90 or higher, pat yourself on the back. If the number is lower than 90 then you should look at changing your cadence. Your cadence does not have to be exactly 90, and is likely to change somewhat with your pace and terrain. A faster pace may have a higher cadence, as will up or down hill sections.   
 
=Measuring 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. ([[RunScribe]] 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.)
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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]].
==Comparison of Cadence Monitors==
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[[File:Cadence Comparison.jpg|none|thumb|500px|See my [[Comparison of Cadence Monitors]] for more details on the accuracy of [[Best Running Watches| watches that measure cadence]]. You'll find more detail, such as this comparison during a [[High Intensity Interval Training]] session.]]
[[File:Cadence Comparison.jpg|none|thumb|1000px|A comparison of cadence monitoring devices during [[High Intensity Interval Training]].]]
 
The graph above is from a [[High Intensity Interval Training]] session, which is a challenging test of Cadence monitors. The [[Warmup]] 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 more normal 90, then a further drop as I walk for a short period before commencing 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 [[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 that also monitors 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 responses, 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 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 Comparison3.jpg|none|thumb|1000px|A second comparison of cadence monitoring devices during [[High Intensity Interval Training]].]]
 
The graph above is another test during a [[High Intensity Interval Training]] session, and again, the [[Warmup]] and [[Cooldown]] sections of the run are not included. You can see that under steady state conditions, all the watches do reasonably well, but not during the interval section.
 
* I wore five watches, only one with a [[Footpod]] and the others with just their internal sensors.
 
* The orange line is from a [[Garmin 920XT]] with a Garmin Footpod. This is the gold standard for this run and I'm assuming it's accurate based on the tests above.
 
* The purple line is from the [[Suunto Ambit2]] and matches fairly well with the Footpod.
 
* The red line is from a [[Garmin Epix]] which does nearly as well as Ambit2, but there are a couple of drop outs where it thinks the cadence has dropped rather than gone up.
 
* The blue line is from a [[Garmin 225]] and it does quite poorly, not really following the interval session at all.  
 
* The green line is from an [[Suunto Ambit3]] where again you can see it loses touch with reality 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 Run]].]]
 
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.
 
[[File:CadenceV800.jpg|none|thumb|1000px|The [[Polar V800]] cadence compared with a Garmin as a reference.]]
 
The [[Polar V800]] provides reasonably good tracking of Cadence, though it is biased a little high. For this example run it had an average of 95.5 rather than 94.6. The V800 tracks the walking break at 20 minutes, the faster pace at 30 minutes, and the [[Fartlek]] beginning at 50 minutes.
 
I plan to perform further tests of the internal accelerometer based devices as time allows.
 
 
=Changing Cadence=
 
=Changing Cadence=
 
There are several ways of changing your cadence.
 
There are several ways of changing your cadence.

Revision as of 05:37, 30 May 2016

Cadence is simply how often your feet touch the ground, but it has a profound impact on your Running Form and Running Economy.

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.

1 Correct Cadence

So what should your cadence be? It's generally accepted that a turnover of 90 steps/minute is optimum for most people (180 steps/minute if counting both feet). To start off, check your cadence when you are running and if the number is 90 or higher, pat yourself on the back. If the number is lower than 90 then you should look at changing your cadence. Your cadence does not have to be exactly 90, and is likely to change somewhat with your pace and terrain. A faster pace may have a higher cadence, as will up or down hill sections.

2 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 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.

See my Comparison of Cadence Monitors for more details on the accuracy of Best Running Watches. You'll find more detail, such as this comparison during a High Intensity Interval Training session.

3 Changing Cadence

There are several ways of changing your cadence.

  • To increase your cadence, focus on smaller steps rather than running faster. Initially this will feel strange, but it will become natural with time.
  • The easiest way to get the right cadence is to run with a metronome, which sets the pace for you. An example of a small metronome would be the Seiko DM50 Metronome. I trained for several months with a similar device, and it helped me immensely. I found it rather loud, so I wrapped it in duct tape to quieten it down.
  • A metronome app for a smartphone works and is cheaper, but verify that the app is accurate as there are reports of some that do not keep time correctly.
  • Some 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 remix music so that it is a higher tempo.
  • 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.

4 The adaptation 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.

5 The Science of Running Cadence

Jack Daniels[1] (the coach not the distiller) found that the slower the cadence, the longer you are in the air and the harder you land. Slow turn over means more impact, which causes more injury. If you take this to the extreme ("Reductio ad Absurdum"), imagine running with just one step per minute. You would have to leap high in the so that you would be in the air for 30 seconds; the landing force would probably break your legs.

  • Scientific studies have backed this up, showing that an increased cadence reduces the impact forces of running[2][3]
  • The peak impact force at a cadence of 88 being just over half that that of a cadence of 64[4].
  • A higher cadence also reduces peak leg deceleration as well as peak impact forces in the ankle and knee joints[5].
  • Higher cadence is also related to a reduction in Overstriding[2].
  • A cadence of around 90 is also associated with greater running efficiency than lower or higher cadences[4].
  • Not surprisingly, a higher cadence reduces Delayed Onset Muscle Soreness and the associated weakness[6].
  • One study[7] 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[3].
  • The impact forces at a longer stride length are mostly absorbed by the knee[8].
  • Adding extra weight to the ankles of recreational runners did not change their Cadence or stride length at various speeds[9]. The study showed that Cadence remained nearly constant while stride length increased with speed, with or without weights of up to 1.1 kg/2.4 pounds.
  • 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[10].
  • Barefoot running tends to have a higher cadence than shod[11].
  • 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 [12].
This chart[3] 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.
A chart showing the oxygen cost and heart rate for different cadences. (Cadence values in red added)[4].

6 References

  1. Jack Daniels Running Formula (second edition) Page 93-94, "Stride Rate"
  2. 2.0 2.1 BC. Heiderscheit, ES. Chumanov, MP. Michalski, CM. Wille, MB. Ryan, Effects of step rate manipulation on joint mechanics during running., Med Sci Sports Exerc, volume 43, issue 2, pages 296-302, Feb 2011, doi 10.1249/MSS.0b013e3181ebedf4, PMID 20581720
  3. 3.0 3.1 3.2 JA. Mercer, P. Devita, TR. Derrick, BT. Bates, Individual effects of stride length and frequency on shock attenuation during running., Med Sci Sports Exerc, volume 35, issue 2, pages 307-13, Feb 2003, doi 10.1249/01.MSS.0000048837.81430.E7, PMID 12569221
  4. 4.0 4.1 4.2 Hamill, J., T. R. Derrick, and K. G. Holt. "Shock attenuation and stride frequency during running." Human Movement Science 14.1 (1995): 45-60.
  5. TE. Clarke, LB. Cooper, CL. Hamill, DE. Clark, The effect of varied stride rate upon shank deceleration in running., J Sports Sci, volume 3, issue 1, pages 41-9, 1985, doi 10.1080/02640418508729731, PMID 4094019
  6. Ann V. Rowlands, Roger G. Eston, Caroline Tilzey, Effect of stride length manipulation on symptoms of exercise-induced muscle damage and the repeated bout effect, Journal of Sports Sciences, volume 19, issue 5, 2001, pages 333–340, ISSN 0264-0414, doi 10.1080/02640410152006108
  7. http://journals.lww.com/acsm-msse/Abstract/1999/12000/Plantar_loading_and_cadence_alterations_with.20.aspx Plantar loading and cadence alterations with fatigue
  8. TR. Derrick, J. Hamill, GE. Caldwell, Energy absorption of impacts during running at various stride lengths., Med Sci Sports Exerc, volume 30, issue 1, pages 128-35, Jan 1998, PMID 9475654
  9. 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 2674599
  10. A. G. Schubert, J. Kempf, B. C. Heiderscheit, Influence of Stride Frequency and Length on Running Mechanics: A Systematic Review, Sports Health: A Multidisciplinary Approach, volume 6, issue 3, 2013, pages 210–217, ISSN 1941-7381, doi 10.1177/1941738113508544
  11. C. Divert, G. Mornieux, H. Baur, F. Mayer, A. Belli, Mechanical comparison of barefoot and shod running., Int J Sports Med, volume 26, issue 7, pages 593-8, Sep 2005, doi 10.1055/s-2004-821327, PMID 16195994
  12. 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 8699842