HR and Power zones seem to be incongruous

I rode my bike outside yesterday. The ride was hard, it felt like a threshold workout. When I look at the graph of my HR data and power data in Garmin Connect, the power data makes it looks like I was out for a leisurely stroll but the HR data looks like a threshold workout. My threshold power in Garmin is set to the same value as Xert.

Is Xert making my threshold power too high?

How do indoor workouts compare in regard to data analysis versus RPE?
Does an indoor workout with over/under TP intervals feel about right? What about over/under LTP?
Are indoor workouts on same bike/meter with power match enabled?

HR/RPE is higher than what my power is telling me on indoor workouts but it’s not as big a difference as on the outdoor rides.

Not sure about the over/under workouts. I haven’t done those in a while so I’ll do one and report back in a few days.

Indoor and outdoor rides are done on different bikes. Outdoor is road bike with pedal power meters, indoor is on my old road bike with Kickr Core that gives me the power, cadence, etc…

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You could move your power metered bike to the Kickr (or just the pedals) and test the difference in watts between the two sources.
A non-tech way is to run EBC and during a workout (over/under or straight block intervals) select Sensors and toggle between Power paired to the pedals versus the trainer.
When paired to the pedals Powermatch is enabled. Note the difference in RPE. Which connection feels harder?
The more accurate method is to dual record the workout and use DCR Analyzer or Compare the Watts to view the two recordings and determine % delta.

Thank you for that suggestion. I’ll put the pedals on my trainer and use the tool you suggested. I’d never heard of them. Thanks again. I’ll report back when I have the data to share.

MB

I put my outdoor bike on my training and did an over under ride as you suggested. While I was riding, I was watching the power readings from both the Vector3 pedals and from the trainer. The pedal power was consistently 10 watts lower than the trainer power.

I recorded the trainer data with the Xert app and the pedal data on my Garmin watch. I then loaded the data into DCR analyzer and it also shows that the Vector pedals are consistently 10 watts lower. Here is a link to the DCR analysis:

DC Rainmaker Analyzer

Here is a portion of the power comparison chart:

And also I paid attention to RPE and it seemed to track more closely with the trainer power. Do I need to have 2 different sets of power zones, one for inside and the other for outside?

Looks like 8% difference assuming similar results across a range of target watts.
Does it help any if you calibrate the pedals and trainer after a warm-up (if not an auto-calibration model)?

I actually did calibrate both the pedals and the trainer before the ride. Sorry i should have said that in my previous message.

Not sure you can do that with Xert (?).

It may not seem like it immediately but you may be better off just switching pedals between bikes, so you have the same source for all activities.

I have different PM pedals but another thing to check is your setting for crank length. That could be the source of the difference, and even if not, you could fudge it so it reads higher (increase it 8% or whatever difference you have). Of course you don’t know which reading is ‘right’ but higher always sounds better :blush:

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Thanks for that advice on crank length. When I checked the vector pedal settings the crank length was set to 172.5. When I looked on the crank it is actually 175mm. I changed the setting and I’ll go for a ride later to see what change that makes to the power readings.

Thx,

MB

I think that won’t explain the full difference as it’s only about 1.4%, but you can still use it to fudge the power from your pedals

Ok thx Wes. So does anyone have a recommendation for which one is more accurate for power, the vector pedals or the wahoo kickr core trainer? The trainer aligns better with my RPE but I’m not sure how much i trust my RPE (:slight_smile:

For training it doesn’t really matter as long as it’s consistent. And given you can’t fudge the Kickr readings you’ll need to go with those and fudge the PM pedal readings (assuming you don’t want switch pedals between bikes).

Optionally if you go down that route, you may want to check whether your signature needs adjusting depending on which PM your last BT was with… over time your signature will align assuming you get new breakthroughs, so that’s just relevant for the start point.

Or, as mentioned, it may better to just switch pedals between bikes, no fudging required. (That’s what I do, but actually don’t see material difference between Kickr and Assiomas duos…, triggered another thought, do you have dual or single sided PM pedals? A left right imbalance can also skew things, sometimes materially, in which case the Kickr should be more accurate)

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