Sorry for the rather long post…
First of all, thank you for your efforts in building this extension and making it available. Really appreciate it.
I’ve been playing with it and have some questions and potential ideas for improvement if you are open to the feedback.
I downloaded a .fit file viewer so I could visualize the actual values that were being exported and noticed that there may be some discrepancies between the intended outdoor workout ranges, and what the extension spits out.
It appears from the values I see, the extension takes the target power value and sets it as the “custom_target_value_low” and then sets the “custom_target_value_high” as the low value +10% (or whatever you set the extension options to in the pop up window). Unfortunately, I do not think this is what wahoo has intended… and likely doesn’t align with the outdoor workout ranges someone would see on a Wahoo head unit. (I don’t have a wahoo computer, so I can’t check this right now…)
On their website, wahoo explains how they modified their indoor workouts for outside. See here:
How the target ranges are calculated:
FTP is broken into 5 broader zone ranges. This allows users more flexibility in following the workout correctly. It also reduces the number of intervals each session has to make them easier to follow outside.
- Zone 1 = 30-50% of target value
- Zone 2 = 51-75% of target value
- Zone 3 = 76-91% of target value
- Zone 4 = 92-101% of target value
- Zone 5 = 102-108% of target value
MAP is +/- 5% of target value
AC is +/- 8% of target value
NM is +/- 10% of target value
Based on this, I imagine your extension could/should be modified to follow the strategy above. If I am interpreting it correctly, I assume this means that the target power would be at the exact center of the power range for any given workout step. Then, the “low” and “high” power values would be equally spaced below and above the target power based on the breakdown above. This seems to be relatively straightforward for any workout steps that are considered MAP, AC, or NM focused, since the ranges simply apply a consistent +/- percentage around the target value for the particular workout step. However, it seems they further broke down the FTP focused steps into 5 zones. Currently, I interpret this in the following way:
It seems there are only 5 potential “Zones” that any FTP focused workout step can be set at. I believe the “zones” are equal to what is shown above, where “target value” represents the 4DP FTP value for the rider. For example, if your FTP is 300 watts, the zones would be the following:
Zone 1 range: 90-150 watts (30-50% of FTP) with target of roughly 40% FTP (120W)
Zone 2 range: 153-225 watts (51-75% of FTP) with target of roughly 63% FTP (189W)
Zone 3 range: 228-273 watts (76-91% of FTP) with target of roughly 83.5% FTP (250W)
Zone 4 range: 276-303 watts (92-101% of FTP) with target of roughly 96.5% FTP (290W)
Zone 5 range: 306-324 watts (102-108% of FTP) with target of roughly 105% FTP (315W)
It appears that these are the only possible workout ranges (for any FTP step) that would be used for this person who has an FTP of 300 watts. Any FTP focused workout step would have to match one of those ranges. This seems to make sense when you compare the graphs between Indoor and Outdoor workouts below (the number of steps are reduced, and the only remaining steps match one of the zones above). For the extension, you would need to apply the appropriate range around the target value, depending on which of these 5 zones the target falls within. So for example (for the 300w FTP person), if the output from systm shows a target power for a given workout step as around 120 watts, you know that it must be centered in zone 1, so you’d apply the 90-150 watt range to that particular step. This could be applied to any FTP step, based on which zone it falls into. Obviously, the ranges and target values would shift depending on the actual FTP value in someone’s profile.
Maybe the extension pop up window could be modified to allow the user to customize the ranges around each portion of their 4DP profile values, with some way to allow the further breakdown of the FTP section into the 5 zones shown above. I think the main change needed would be the ability to adjust the range that is applied above AND below the target, instead of the current output that only adds the range above the target power value. You could potentially have 8 ranges to modify (the 5 FTP zones, MAP, AC, and NM). Or, take away the ability for the user to modify, and simply apply wahoo’s strategy above which should match with the intended workouts sent to wahoo units.
If the extension were updated, it would be interesting to compare to the actual workout sent to a wahoo unit to verify, so maybe that could be a future test someone with a wahoo computer could do.
It also does not seem to be tracking the cadence targets. Is that possible to do?
Hopefully all this makes sense. I do not intend to criticize your extension, but instead help improve it to match what someone would see on a wahoo unit. Would love to hear your thoughts and would be happy to help collaborate on the extension to get it dialed in if I can help in any way.
Thanks so much,