DSW mismatch with TE

Doktacillin said:

For instance, a few days ago I was supposed to run 10 min zone 2 warm up, 2x18 min at 4 BPM below threshold HR with 5 min zone 1 in-between and 10 min zone 2 wind down. I think it was supposed to be about 4 TE aerobic. It came out at 4.9 TE aerobic and 2.3 anaerobic

In short, the most usual suspect is the Max HR or Rest HR. If the TE is consistently over reported (workouts feel easier than reported), the Max HR is not high enough or the Rest HR is too high, and vice versa.

More details:

There are 2 main layers:

- the calculation of the training effect for the aerobic system and the anaerobic system: the training effects are calculated based on the peak Estimated Postexercise Oxygen Consumption (EPOC, essential impact) and the average training load of the user (minor impact). EPOC is estimated based on fixed parameters like Max HR and Rest HR, workout HR/HRV data, and, to a great extent, pace/power data for the anaerobic TE for biking and running activities only.

- the determination of the workout label based on the training effect is based on multiple rules involving multiple aspects of the EPOC dynamic during the workout, and to a second level of impact LTHR and/or power/pace at threshold for biking and running.

As you can see there are a lot of ways the TE might be estimated very differently from the expected TE of a given workout.

The first thing to understand is that HR training zones only set expectations, regardless of the type of zone definition. They, or the time in zone, are not used to calculated the training effect or the workout label.

So, here is what a user should do to maximize the chances of an accurate TE calculation:

- enter an accurate Max HR,

- have an accurate Rest HR by wearing the watch all the time,

- use a chest trap during all workouts not only to improve HR/HRV data capture, but also to maximize the accuracy of the Max HR and LTHR auto-detections

- follow a balanced training program to expose the watch to a variety of efforts, so that the relationship between ventilation, output for running and biking (pace/power) and duration is not biased.

- from time to time, replace the effort level for a given set of intervals in a DSW by a maximal steady effort. This is because, although the watch is pretty good at estimating "max effort" things like VO2 max, Max HR, LTHR from sub-maximal efforts, the accuracy of the estimates will be higher when maxish efforts are used. Only trained athletes can managed "safely" max efforts, so check with your doctor if you are not used to them.

Max HR auto-detection: compare your number with the peak HR from your last 5K ran as fast as you could until your dropped. Your PB peak HR should be about 5bpm lower than your Max HR.

LTHR auto-detection: compare with your average HR during the second 19mn interval, if the interval was a maximal steady effort. You average HR multiplied by 0.95 should be close to your LTHR (a true LTHR test would be 30mn maximal steady effort, that the average of the last 20mn, multiply by 0.95).

I'll answer in bullet point form:

• Accurate maxHR - as accurate as can be. It has been 186 BPM since I bought the watch and I verified the maxHR yesterday when I did a maxHR-test. No change at all.
  
  
• I’ve been wearing the watch 23-24h/day since early July
  
  
• I’ve been wearing a HRM-Dual during all workouts since early August
  
  
• I’ve been using DSW almost entirely for my running since July
  
  
• Maximal steady effort? Like max out for the interval instead of for instance threshold pace according to DSW? Or what's the definition of maximal steady effort? 
  
  
• I checked a 6k race I ran in July, peak HR was 185, maxHR yesterday was 186.
  
  
• My average HR during the last 18 min interval was 168 BPM at a 3:51 pace. I’m not sure it was a maximal steady effort - I notice that my breathing becomes different when I go above 174 BPM (i.e. the estimated LTHR from the watch at 172-173 BPM seems to be correct). The threshold runs, when using HR-guided DSW, seems to aim for LTHR minus 4 (target HR 169 BPM).