Hi Alex,
I am wondering why, in the TrainerDay calendar, some of my endurance rides imported from Strava are shown with “Dominant zone: anaerobic”. If you look at the attached screenshot, you can see that this was more or less a Z2 ride.
This happens with a lot of my Strava rides (even with some of my short commutes), but not with all of them. Additionally, the stress for all Strava rides is shown as zero in the detail view, even though it is shown correctly in the calendar overview.
So about 8 years ago I worked with Mark L at Golden Cheetah they did a bunch of calculation on a 1,000 riders to determine dominant zone relative to what has the most impact on the body related to power duration curve or something, I don’t remember the exact details. I could find more info.
In that ride you did 38 seconds above 120% (336–572 W). Based on the math that has more effect than 20 minutes of tempo. But this math was for structured workouts so I agree in this case with very short bursts we probably need to re-look at this. If it was 38 seconds in a row it might be true.
It’s not really an issue for me, so don’t spend too much effort into it. I just stumbled over the red bar and was wondering why the same ride was colored green in intervals.icu.
Actually I am analyizing this now. I have not looked at this in many years. I am realizing this is not great for general rides, but also intervalsICU skews things the wrong way as well I believe. The problem is there is no “right” when it comes to the idea of “dominant zone” really that should be relative to how you ride. If you ride 6 hours every day in zone 2 and all of a sudden do 2 hours zone 2 and 30 seconds at 120% the for YOU the dominant zone or the zone that had the most affect would be VO2max. But we should probably improve this. The simplified method now would be more like scaled time in zone by intensity factor.
So your ride would look like below, so dominant zone would be Z3 and likely match closer to your expectations but still weighted fairly heavily.
Weighting: Power⁴
Z1: 5%
Z2: 22%
Z3: 32%
Z4: 22%
Z5: 9%
Z6: 10%
I think I will change it like this after doing more analysis.
