Vigorous days and fitness age.

I tried to find the definitions of vigorous days but failed. I only found this in a forum post:

"30 minutes of vigorous activity 3 days per week averaged over the last 4 weeks"

https://forums.garmin.com/outdoor-recreation/outdoor-recreation/f/fenix-6-series/274772/vigorous-activity-definition-for-fitness-age 

That definition can be interpreted in several ways, but if you at least do 3 activities per week with 30 vigorous minutes each time for 4 weeks you should be guaranteed to get a checkmark for vigorous days.

Mines done the same in the last 24 hours for no reason

My fitness aged increased by four years and my vigorous days dropped to zero and stayed like this until doing some exercise which was not recorded on my watch, just pick up as intensity minutes. After this my fitness age went back to what it should be with the correct vigorous days.

I have just put a new weight in again and the same problem has occurred so for me, at least, it appears to be a bug when entering a new weight. 

Same problem for me.

Mine fixed itself overnight for no apparent reason 

I’m having the same issue, it appears to reset weekly on Sunday night instead of taking the last 4 weeks into account like the vigorous minutes do.

FYI according to Garmin, a “vigorous day” is when you have a day with at least 5 minutes of continuous vigorous activity.  

Do you have any source to that information? 5 minutes sounds like very few minutes.

I correct my post. You are right it should be the 4 week average.

e7andy said:

Do you have any source to that information? 5 minutes sounds like very few minutes.

The original method for the Fitness Age used the VO₂max only. The new method using vigorous days, BMI, and RHR, seems to be still in the finetuning process, and the description changes over time. And the algorithm likely too. The earlier description of the Fitness Age referred both to 5 continuous vigorous minutes, as well as 15 vigorous minutes in a 30-minute time period, but recently the 5 min specification disappeared from the Fitness Age help screens in Garmin Connect, hence the exact conditions are uncertain.

Though, the page about the Fitness Age on the Health Science website of Garmin, still mentions the 15 minutes in a 30 min period, so perhaps it is the right method currently used.

You can see both those descriptions for example in the thread Achievable Fitness Age