HR zones after training differ from the HR set zones

macmanaman said:

My Fenix 7 with last SW installed doesn´t show the same HR zones set by me in the results after a run. Is someone experiencing this problem?

What are your HR Zones based on? If it is the LTHR or the Max HR, and you did not disable the auto-detection of those values, then the HR Zones will indeed dynamically adjust.

macmanaman said:

I haven´t found how to upload images to show the problem.

Copy the image and paste it into the message box.

Hi Trux,

No, all auto detection are disabled. I have disabled them because they reset my HR zones even when max HR didn´t changed. My HR zones are based on the max HR defined by me.

Thanks for answering and regards.

Frankly told, the HRZ table shown on the second screesnhot makes little sense (i.e. the zone 3 is set to 90%-90%, etc). I recommend resetting it.

I see....  What is happening then is that HR zones change even when auto detection is disabled for all the options.

This is how I set them. I am sure my device keeps changing them. I will observe what happens after next run.

Hi Trux,

Today after a 36´ run HR zones didn´t change. I will keep looking closely to see what triggers the HR change.

HR zones settings is only because a colleague explained how to do a test to look for the MAX HR and then according to him I should set the Zones like that. I can´t provide any insight on why is like that.

Thanks for your help.

macmanaman said:

HR zones settings is only because a colleague explained how to do a test to look for the MAX HR

Your colleague is right when he tells you to do a test for HR Max. This is the best way to set the value on the watch and it is the most important parameter you need to enter to get the metrics about right, aside from good HR and pace/power data as you exercise.

The way you set up your training zones has no impact on the watch metrics, so they are only useful to design your workouts. The watch will determine by itself, without using your zones, in which physiological training zone you are.

There are essentially 3 physiological thresholds for training purposes. The first ventilatory threshold when the respiration rate starts increasing faster (aka aerobic threshold), the second ventilation threshold (essentially the same as anaerobic/lactate threshold) and VO2 Max (maximum ventilation)

In endurance sports, you train to create adaptations in the body so that your thresholds increase.

For all intent and purposes, leaving the HR zones as % of HR Max by default on the watch is better for most people. The rest will work with lab data to optimize the system, but will need regular resting to reflect the adaptations. For the rest of us mortals, the default are just very good.

Since HR Max can be hard to determine, LTHR zones are easier to set, reflect best your current fitness and most often used in training plans. % HRR has the benefit to be the closest to the % of VO2 Max which is what the watch uses internally but depends on both HR Max and Resting HR...

macmanaman said:

HR zones settings is only because a colleague explained how to do a test to look for the MAX HR and then according to him I should set the Zones like that.

I am sorry, but that's absolutely wrong, and it may skew some Garmin metrics. Z5 starts normally around there where your LTHR is (Lactate Threshold HR). Best is conducting the LTHR test, and basing your HR Zones on the LTHR. But if you want to continue using the HR Max as the base, then the Z5 should start around 90% of Max HR up to some 120% or more (yes, the HR can go briefly over the Max HR). Keeping the Z5 from 100% to 100% of the Max HR means that you actually work with four HR zones instead of five.

I recommend using the default percentages as set by Garmin when you reset the zones - those values are based on serious scientific research. If you do not trust those values for some reason, do some reading online - there may be alternative solutions, but I do not believe you will find a zone table with Z5 starting at 100% of Max HR.

heart rate zones - Google Search

A detailed description of individual HR Zones is available also directly at Garmin:

How Are Heart Rate Zones Used With My Garmin Device? | Garmin Customer Support