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Running Economy

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* '''High Intensity Interval Training'''. There are a number of studies that have shown that [[High Intensity Interval Training]] improves running economy.
=Measuring Running Economy=
In an ideal world, we'd be able to easily measure our [[Running Economy]] and see if things are improving. If we could measure our breath, find out how much O<sub>2</sub> we consumed and how much CO<sub>2</sub> we produce, we'd know how much energy we burned (and from fat or carbohydrate). Such testing would require controlling the time of day, day of the week, diet, and footwear for each test<ref name="Pereira-1997"/> as well as specialist equipment that is not available to recreational runners. (Systems such as Cosmed's K5, PONE, and VO2 Master's VM Pro are becoming available, but cost thousands of dollars. Because this is not practical, the best measure we have of energy consumption is our [[Heart Rate]]. This is far from perfect, as [[Heart Rate]] [[Heart Rate Drift| can vary for other reasons besides supplying O<sub>2</sub> for energy production]]. However, I believe it is a useful approximation and so I developed the simpler "Relative Running Economy."I've created an improved version called "HR-Pwr" which used the power estimate from [[Stryd]] to give a more useful estimate. =HrPwr Estimate of Running Economy=My initial approach was to use heart rate to estimate energy cost and distance covered to measure the effort. This works okay on the flat, but is thrown off by changes in elevation. The [[Stryd]] footpod estimates the power output based on pace and elevation changes, which solves this problem nicely. It also gives the possibility of comparing data from running with cycling, though I've found the Stryd power estimate to be much higher for a given perceived effort than cycling. The formula I use is milliwatts per Kg per heartbeat, which I've called [[HrPwr]] (It's available as a [[Connect IQ]] data field.)
=Relative Running Economy=
Given the difficulty of measuring Running Economy, I have developed a simple alternative that provides a relative value for Running Economy. This Relative Running Economy calculates a value based on how many heart beats are used for the distance covered. The formula that is shown below and there are more details at [[Relative Running Economy]]. <blockquote><code> Total Beats = (Average [[Heart Rate]] – [[Resting Heart Rate]]) * Time in Minutes<br> Work Per Mile = Total Beats / Distance in Miles<br> Efficiency = 1 / Work Per Mile * 100,000<br></code></blockquote>
Note that the difference between Heart Rate and [[Resting Heart Rate]] is used to calculate the heart beats used for movement. Ideally the Heart Rate for standing would be used, but typically Resting Heart Rate is taken seated or lying down.
=How to use Relative Running Economy=
The calculated [[Relative Running Economy ]] cannot easily be used to compare different runners. It can be used as to track how your running economy is improving over time, though it is also influenced by changes in fitness. Over the weeks and months of training your Relative Running Economy should gradually improve. For instance, I've seen my RRE go from 110-120 to 130-150 over a period of a few months. Sadly, I've also seen my RRE drop when I put on body fat (see [[Weight Loss and Performance]].) This evaluation of my fitness this proved to be remarkably useful to me.
=Relative Running Economy to detect Glycogen Depletion=
Another use for the Relative Running Economy is to compare values within a run. [[Glycogen]] depletion will result in a drop in efficiency, and this can be seen in the efficiency value. The glycogen depletion causes more fat to be burned, and fat requires more oxygen to provide an equivalent amount of energy. The graph below shows my efficiency value during a long run, consisting of pacing a 3 hour marathon, then adding on 9 extra miles at a slower pace. You can see my efficiency value staying reasonably constant, with some variation for the hills, until about mile 19. From 19 to 26 you can see my efficiency value gradually dropping due to [[Glycogen]] depletion. After the marathon distance you can see some recovery as I refuel somewhat.
[[File:Efficiency and glycogen depeletion.jpg|none|thumb|300px|Efficiency value over a 35 mile run.]]
=Billat's Cardiac Cost=
Veronique Billat produced a similar formula called "Cardiac Cost" in a research paper on marathon pacing<ref name="BillatPalacin2020"/>. The formula
Cardiac Cost = Heart Rate / Speed * 6000
Where the speed is in meters per second. The formula does not adjust for [[Resting Heart Rate]], but otherwise will result in
=References=
<references>
<ref name="BillatPalacin2020">Véronique Louise Billat, Florent Palacin, Matthieu Correa, Jean-Renaud Pycke, Pacing Strategy Affects the Sub-Elite Marathoner's Cardiac Drift and Performance, Frontiers in Psychology, volume 10, 2020, ISSN [http://www.worldcat.org/issn/1664-1078 1664-1078], doi [http://dx.doi.org/10.3389/fpsyg.2019.03026 10.3389/fpsyg.2019.03026]</ref>
<ref name="Saunders-2004"> PU. Saunders, DB. Pyne, RD. Telford, JA. Hawley, Factors affecting running economy in trained distance runners., Sports Med, volume 34, issue 7, pages 465-85, 2004, PMID [http://www.ncbi.nlm.nih.gov/pubmed/15233599 15233599]</ref>
<ref name="Daniels-1985"> JT. Daniels, A physiologist's view of running economy., Med Sci Sports Exerc, volume 17, issue 3, pages 332-8, Jun 1985, PMID [http://www.ncbi.nlm.nih.gov/pubmed/3894870 3894870]</ref>
<ref name="Jones2006">Andrew M. Jones, The Physiology of the World Record Holder for the Women's Marathon, International journal of Sports Science and Coaching, volume 1, issue 2, 2006, pages 101–116, ISSN [http://www.worldcat.org/issn/1747-9541 1747-9541], doi [http://dx.doi.org/10.1260/174795406777641258 10.1260/174795406777641258]</ref>
<ref name="Pereira-1997">MA. Pereira, PS. Freedson, Intraindividual variation of running economy in highly trained and moderately trained males., Int J Sports Med, volume 18, issue 2, pages 118-24, Feb 1997, doi [http://dx.doi.org/10.1055/s-2007-972606 10.1055/s-2007-972606], PMID [http://www.ncbi.nlm.nih.gov/pubmed/9081268 9081268]</ref>
</references/>
[[Category:Science]]

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