Vigorous minute calculation has changed in last few months

7736948 said:

Was this a default change after a firmware update?

Fwiw I'm on the latest beta firmware, I've never changed that setting, and for me, the setting is still "don't use HR zones".

I haven't reset my device to default settings during that time, so I can't say for sure whether the default has changed or not.

7736948 said:

Does is make sense that Z3 is mod and Z4 is vigorous?

It doesn't make sense to me, as it will completely exclude activities like runs which stay in zone 2 or lower (regardless of length), and as you noted, it produces wildly different results in the intensity minutes calculation compared to the default.

e.g. If you run a long Z2 training run for 3 hours as part of marathon training, you will get 0 intensity minutes. From a common sense POV, this is ridiculous. It's as if running easy (or perhaps moderately hard) for 3 hours is no different than sitting on the couch and binge-watching reality TV.

Maybe Garmin thinks it makes sense, idk. For an objective assessment of this, apparently the American Heart Association defines...:

- moderate exercise intensity as 50% to about 70% of max hr

- vigorous exercise intensity as 70% to about 85% of max hr

[https://www.mayoclinic.org/healthy-lifestyle/fitness/in-depth/exercise-intensity/art-20046887]

Garmin's default values for zones based on max HR are:

Z1: 50-60% of max HR

Z2: 60-70%

Z3: 70-80%

Z4: 80-90%

Z5: 90-100%

By the AHA definition and Garmin's zones definition, moderate should be Z1 and vigorous should be Z3-ish. Having moderate start at Z3 sounds completely wrong to me.

The same page linked above says that moderate aerobic activity includes brisk walking and mowing the lawn. I think if you're in decent shape, it would be pretty tough to hit Z3 during walking and mowing the lawn....

If I were you I'd just change it back to the way it was, or select lower zones.