I just learned that I cannot generate a custom data field with the Running Efficiency Index (basically EI = speed [m/min] / power [W]), since Appbuilder has no access to the Garmin Running Power app power variable. Reading the thread here, I guess that this is simply not feasible without having the Connect IQ power calculation natively integrated into the 935 firmware. Are there any plans to do so? Current power without wind speed consideration would be absolutely sufficient for a start.
In summary: The authors calculated that the total running power given by the Garmin Running Power app is about 30 % higher than the theoretical one as well as that provided by the Stryd foot pod (negligible wind speed).
These findings are in good agreement with calculations based on my own training runs compared against the Garmin Running Power app output (negligible wind speed). Is the GRP app using higher running resistance power efficiencies or what is the reason for this significant deviation to the fundamental theory? Are there any Garmin or Firstbeat white papers on this topic one may study?
Worstje , thanks for your interest in Garmin Running Power. If you would some more information about how we calculate running power and why running power is higher compared to cycling power (along with why we believe the magnitude of values we see for running power line up with peer reviewed journals) use the following FAQ links:
Calculation Method for Garmin’s Running Power Connect IQ Apps Running Power Higher Compared to Cycling Power
We cannot speak for how others perform their calculations. One thing to note though, the location of the sensor contributes to the measured vertical oscillation, which is a large contributor to total running power. This likely partially contributes to the differences in reported numbers.
Worstje , thanks for your interest in Garmin Running Power. If you would some more information about how we calculate running power and why running power is higher compared to cycling power (along with why we believe the magnitude of values we see for running power line up with peer reviewed journals) use the following FAQ links:
Calculation Method for Garmin’s Running Power Connect IQ Apps Running Power Higher Compared to Cycling Power
We cannot speak for how others perform their calculations. One thing to note though, the location of the sensor contributes to the measured vertical oscillation, which is a large contributor to total running power. This likely partially contributes to the differences in reported numbers.
Thanks for the links and prompt reply, Garmin-Joey!
Unfortunately, there is neither any information on the physics (equations) used (in the app) nor on how running efficiency is taken into account in the Garmin Power app: is it a fixed value like 3.6 J/kg/m (as suggested by different authors) multiplied by some efficiency factor or is it a specific friction coefficient employed in the running power equation?
The publications you cite apparently do not support the high power calculated by the Garmin Power app (cf. http://fellrnr.com/wiki/Running_Power_Meters#Running_and_Cycling_Watts). I have tested the Running Power Estimator II app together with the Stryd Power app (with the Stryd foot pod). Both provide almost identical results, while the Garmin Power app shows similar trends but much higher values (> 30% higher). This cannot(!) result from lower distance/pace accuracy when comparing the FR935 GPS and the Stryd foot pod sensor, but mainly from the underlying physics.
I would be very grateful about more transparency on how the Garmin app calculates the basic running power, and especially the option to adjust the efficiency factor (if any), so that running effectiveness (RE [kg/N] = Speed [m/s] / Power [W/kg]) and running efficiency (EI = Speed [m/min] / Power [W]) become reasonable data with the FR935. Both are important (at least for me) to monitor my improvement in running economy. I am aware that also higher values allow to do so, but for RE it is important to have the "absolute value".
Thanks for considering to bring in more transparency into this topic!
I have the 5X+ and both times I've ran with running power it only records the first few minutes of my run and then my watch displays 0 the rest of my run. Anyone else experiencing this? Any suggestions?ciq.forums.garmin.com/.../1383765.png
is your phone connected via bluetooth LE to your phone while you are running? Many people that report this bug (it doesn't impact me with my HRM-Run and 5x+) also report that disabling the connection from the watch to the phone solves the drop of running dynamics and power that happens at around 2ish minutes.
