I don’t now if it was a bug but while siting at my computer, my intensity minutes spiked. Yes my job can be stressful, but it should not create intensity. Was I fidgeting? The answer is really I do not know.

Intensity Minutes

Although I have sports goals for next year, my main goal is the exercise for longevity. What I have learned over the years, especially for my health, is that things not measured, no change happens.

I am a big fan of minimums. At my age, AARP suggests minimums of 5,000 steps. The CDC suggests 150 moderate/75 vigorous. Both not hard to accomplish. (As of this post, I have done 16,291 steps)

From what I understand of how Gamin calculates intensity minutes, it is based on resting heart rate. Mine is very low. I am thinking that maybe, it is messing with the algorithm.

Garmin also allows you to set what counts as intensity minutes by heart rate zone. When searching the web, there was no good answer. So I asked both Copilot and Grok. I liked Grok’s answer better.

Question: What Garmin heart rate zones are considered moderate and vigorous intensity?

Grok’s Answer

Garmin uses a default 5-zone heart rate system based on percentages of your maximum heart rate (HRmax) or, if you’ve set it, your lactate threshold heart rate (LTHR). Most users rely on the default % of HRmax zones unless they’ve manually switched to LTHR-based zones.

Here are the standard Garmin heart rate zones and how they map to exercise intensity guidelines (e.g., CDC, American Heart Association):

Zone% of HRmaxColor on GarminIntensity Level (official guidelines)Description
Zone 150–60%GreyVery light / Warm-upRecovery, easy conversation
Zone 260–70%BlueModerate intensityComfortable, can talk easily (this is the “fat-burning” zone many people refer to)
Zone 370–80%GreenModerate intensity (upper end) / Light aerobicConversational pace, but starting to work
Zone 480–90%OrangeVigorous intensityHard effort, talking in short sentences only
Zone 590–100%RedVigorous intensity (very high end) / AnaerobicAll-out effort, almost no talking

Summary for public health guidelines

  • Moderate intensity: Primarily Zone 2 and Zone 3 (60–80% of HRmax)
    → This is what counts toward the recommended 150–300 minutes/week of moderate-intensity aerobic activity.
  • Vigorous intensity: Zone 4 and Zone 5 (80–100% of HRmax)
    → This counts double (1 minute vigorous = ~2 minutes moderate) toward weekly goals; the guideline is 75–150 minutes/week.

Note: If you’ve configured Garmin to use % of LTHR instead of % of HRmax (common among runners/cyclists who have done a field test), the zone boundaries shift upward. In the LTHR system:

  • Moderate ≈ Zone 2 and most of Zone 3
  • Vigorous ≈ Upper Zone 4 and Zone 5

But for the vast majority of users on default settings, the % HRmax table above is what Garmin displays and what applies.