Minutes with high intensity not registered when calculating fitness age

There are 2 different benchmarks here.

One is the intensity minutes, which using your HR against some default zones ("moderate", "vigorous") to match the general recommendations of the American Heart Association.

support.garmin.com/.../

The other one, is the fitness age, which uses your VO2Max and benchmarks you against a reference population.

https://www.garmin.com/en-US/garmin-technology/health-science/fitness-age/

If your fitness age changes, aside from physiological factors like age and weight, it is because your VO2Max estimate has changed.

It is possible to see larger VO2Max changes when, for example:

- the VO2Max of biking is overriding the VO2Max of running as the default VO2Max because of a more recent update, or vice-versa

- some parameters of the model (like HRMax, age, or weight) changed significantly. HRMax auto-detection can be a culprit.

- the VO2Max model was updated by a recent "real" VO2Max-like effort, like a 5k/10k/15k race, or a trail race.

In addition, it looks like your watch is seeing a lack of high intensity training. You might be lacking high aerobic and/or anaerobic load. What does your training focus say?

Epix 2 does not use VO₂max for the Fitness Age, it only uses the method called "Improved Fitness Age Using Additional Factors"

m-schr said:

I actually have 5 days a week with more than 40min per day.

You have to record at least 5 minutes of Vigorous Intensity Minutes (not the plain IMs!) within a 30-minute time period to achieve your vigorous intensity objective for that day. It means if you do several times less than 5 vigorous IMs during the day (not within 30 mins), it won't count, even if the sum is higher than 5 vigorous IMs.

trux said:

Epix 2 does not use VO₂max for the Fitness Age

I didn't find anything confirming this. Garmin is not that clear. The link you mentioned quotes "additional factors" on newer devices. Are they additional or different factors?

Research has found these "additional" factors are good predictors of VO2Max

https://www.ntnu.edu/cerg/vo2max

For fun, I just tried the online calculator here

https://www.worldfitnesslevel.org

In my case, this calculator estimated my VO2Max just a tiny bit (2 points) lower than my Garmin VO2Max, but it gave me an additional 10 years of youth, on top of the 9 that Garmin gives me.

So this Garmin fitness age estimate remains mysterious...

Etupes25 said:

I didn't find anything confirming this. Garmin is not that clear.

I'd tell they are quite clear about it. As long as you have a model supporting the "Improved Fitness Age", the definition of the Fitness Age directly in Garmin Connect states this:

Fitness Age
Fitness Age is an estimate of how fit you are compared to your actual age. It takes into account activity intensity, resting heart rate and body fat percentage or BMI. Our Fitness Age feature will explain your score and provide recommendations for improving it.

No word about VO₂max at all. Besides that, the online documentation states this:

The new method for calculating Fitness Age will give more accurate estimates, and past data utilizing the VO2 max method will no longer be displayed in Garmin Connect in favor of the newer more accurate measures.

And, then VO₂max is also no more being displayed on the "On Target" list of individual factors on the FA screen. 

Hello,

thanks for all the advice but that's not all the problem.

Today my fitness age went back to the original state, literrally overnight.

I did not do anything different than in the last 24 month. Just my morning workout with 40min Indoor-Cycling and planks and situps.

It just makes no sense that I have such a hickup while doing what I was doing for month now.

VO2max is unchanged for weeks now.

That is why I think it must be a bug. Wether it is in the Epix software or in Garmin Connect.

As I wrote, VO₂max plays no role in the Fitness Age on your watch. If the page told you yesterday that you did not have enough Vigorous Days, then it means that in the last 7 days there were not three days with at least 5 continuous Vigorous Intensity Minutes done within 30 minutes, and it like that today they already are. Check out your IM history data - it can tell you better.

That is exactly my point. I had enough Intensity minutes because for many months now I have the same exact workouts every morning, every week.

That is why I believe something was corrupt yesterday.

And also check these two activities from the week before:

Friday:

and Wednesday:

There were definatly enough Vigorous Intensity Minutes.

The 5 Vigorous intensity minutes must be logged within 30 minutes, so it is impossible to tell just from the total IM numbers whether it was really that case or not. They were not necessarily missing yesterday. It could have been also for example on 15th. There must be 3 Vigorous days within the last 7 days.

So where do I check?