==Introduction==There are two components to running ability; fitness and economy. Fitness is the ability of our bodies to generate energy for running and is the focus of a lot of our training. Economy is how far and fast you can run with a given amount of energy. Good economy is a critical part of running, and [[Cadence]] is one element I focus on. ==Measuring Efficiency==In an ideal world, we’d be able to easily measure our Because [[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). Sadly, this is not practical, so the best important but so hard to measure we have of energy consumption is our [[Heart Rate]]. This is far from perfect, as [[Heart Rate]] can vary for other reasons besides supplying O<sub>2</sub> for energy production. However, I believe it is a useful approximation. =How to use the efficiency value=The calculated efficiency value cannot easily be used to compare different runners. It can be used as to track how your running efficiency is improving over time. Over the weeks and months of training your efficiency value should gradually improve. For instance, I've seen my efficiency go from 110-120 to 130-150 over a period of a few months. Sadly, I've also seen my efficiency dropped when I put on body fat (see [[Weight Loss and Performance]]developed this simple alternative.) This evaluation of my fitness this proved to be remarkably useful to me. ==Efficiency and Glycogen Depletion==Another use for the efficiency value 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 graph below shows my efficiency value during a long run, consisting of pacing a 3 hour marathon, then adding based on 9 extra miles at a slower pace. You can see my efficiency value staying reasonably constant, with some variation how many heart beats are used 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 covered as I refuel somewhat. described in [[File:Efficiency and glycogen depeletion.jpg|none|thumb|500px|Efficiency value over a 35 mile run.Running Economy]]. ==The Online Calculator==
Assuming you know the distance you ran, your average [[Heart Rate]] and the time it took, you can calculate your efficiency. If you know your resting [[Heart Rate]], enter that as well to optimize the calculation.
<html>
<style type="text/css">
</tr>
<tr>
<td>Average [[Heart Rate]]</td>
<td><input maxlength="3" size="3" name="AverageHeartRate" value="150"></td>
</tr>
<tr>
<td>Resting [[Heart Rate]]</td>
<td><input maxlength="3" size="3" name="RestingHeartRate" value="40"></td>
</tr>
</form>
</html>
=Suunto Ambit App=I have developed two apps that calculate Relative Running Economy for the Suunto Ambit. One calculates a moving average and the other a smoothed current value. =The Garmin Utility==
If you have a Garmin GPS, this utility will analyze the TCX files to calculate efficiency.
[[File:Garmin Efficiency Screenshot.jpg|none|thumb|500px|Screen shot of the Garmin Efficiency Calculator.]]
You can download it from [http://fellrnr.com//Utilities/GarminEfficiency/GarminEfficiency.exe http://fellrnr.com//Utilities/GarminEfficiency/GarminEfficiency.exe]. Look for the tooltips that pop up when you hover over an option; they'll provide some help.
[[File:Garmin Efficiency Tooltip.jpg|none|thumb|500px|An example tooltip that gives help.]]
==The Efficiency Calculation==The formula that is used is<br><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>==A more impressive alternative==[[Alternative Efficiency Calculator]] uses age, gender, and weight to calculate Calories consumed, and therefore estimate the absolute efficiency. While this is more impressive and allows for comparison between runners, it makes quite a few assumptions in the calculations. If you know your VO<sub>2</sub>max, this calculation becomes somewhat more accurate, but should still be considered only a rough approximation. Overall, I believe the simpler approach is better.
