Name: RunPowerModel - Wrist-Based Running Power Meter
Rating: 4.9 (68 reviews)
Author: MHoller

Powered by www.runningwithpower.com, RunPowerModel is your power meter for running or hiking activities, in the form of a data field which integrates seamlessly into your existing activity profiles! It can be used as a wrist-only power meter, or in combination with a RunningDynamics device (Garmin's run pod, HRM Pro/Tri/Run belts...) for more accurate results.

RunPowerModel is not only designed for those who like to run on the streets but especially also for trail runners. The algorithm behind RunPowerModel corresponds to a self-developed semi-analytical physical model. This means that the components behind the final power number are all physically motivated, but some of its parameters are adjusted to yield reasonable results. It was designed and tested to work under and automatically adapt to various conditions, including uphills and downhills of arbitrary inclination as well as technical trails. For runners who also cycle and know their corresponding power output, the values calculated by RunPowerModel are directly comparable to that.

RunPowerModel calculates your running power and derived quantities and displays them on your watch on a single data field. That way, seamless and neat integration into your existing running profile is ensured. You can display and customise the output as follows:
- Current power (rolling average of the last 3 s, 10 s, 30s*, 1 min*, 3 min*, or 10 min*)
- Average workout power*
- Normalized Power (NP)* **
- Intensity Factor* ** (IF, requires an FTP value to be set)
- Training Stress Score* ** (TSS, also requiring FTP value)
You can choose between either displaying each of the single values constantly or the values of choice switching every few seconds (*). The calculated values will show up in your workout summary in Garmin Connect under Connect IQ, together with the total exerted work and burned calories*, an equivalent average flat pace*, as well as the Trail Score (trail / total power) and Running Score (periodic vertical / total power, *).
In addition, you can specify
- A backpack weight;
- Your Functional Threshold Power, either directly in W or your threshold pace;
- If to save battery by updating the display only every few s;
- If the internal instant-pace calculation shall be used on the trail (requires RunningDynamics);
- If wind from the weather information shall be included in the calculation (*).

Please note: 
- If you have a Running Dynamics-delivering device (Garmin HRM Run/Tri/Pro or Pod), the calculations become more precise. 
- For watches without a barometric altimeter the values are less accurate because of the GPS-based altitude readout (even when running completely flat). RunPowerModel has an internal algorithm to reduce this inaccuracy.
- Barometric altimeter accuracy varies between watch types - e.g. the altimeter of a Forerunner 945 generally performs better than that of a vivoactive.
- Your user weight and height has to be correctly set in Garmin Connect, otherwise default values will be used.
- * above: Only for devices with sufficient memory (Forerunner 945, 745, 245 and 645 Music, Fenix 6 Pro)

References:
- ** About Normalized Power, Intensity Factor and Training Stress Score. https://www.trainingpeaks.com/learn/articles/normalized-power-intensity-factor-training-stress/
- The role of elastic energy storage and recovery in downhill and uphill running: https://journals.biologists.com/jeb/article/215/13/2283/10916/The-role-of-elastic-energy-storage-and-recovery-in
- For more information about running with power, have a look at runningwithpower.com