does anyone know with reasonable certainty what Garmin Connect considers as “low aerobic”?
most of the time I’m hovering around “low aerobic shortage” and I’d like to improve on that (assuming they know what they’re talking about).
my naive understanding was that low aerobic is z1 and z2 and high aerobic is z3 and z4 (in the default zones auto generated by garmin). on the internets I also found a few other opinions/guesses, such as percentage of maxHR etc.
does anyone happen to know? please be explicit about guessing/assuming/knowing
thank you all!
PS I know this is far from being an intervals.icu question, but I’ve found this forum to be extremely helpful with more or less everything in the workout measurements universe. I hope it’s ok to ask this kind of questions.
From my experience over 3 years with Garmin Fenix devices, and some of their support docs and videos…
(personal observation, but very high confidence) Load Focus is considered per session – e.g, if a session is judged Low Aerobic, the entire session Load goes into the Low Aerobic bucket.
(support sources below) Load Focus designation for a session is based on the Training Effect of the session (the thing it shows you in the activity summary above the Aerobic and Anaerobic Effect numbers after you save the activity):
Sprint, Anaerobic sessions are considered Anaerobic for the purposes of Load Focus,
VO2Max, Threshold, Tempo sessions are considered High Aerobic,
Base, Recovery sessions are considered Low Aerobic.
As you can imagine, this is not the most accurate way of assigning buckets, as there is no way to tell how it will designate, for example, a 2-hr Endurance/Z2 session with a handful of VO2Max intervals at the end – is it Base (Low Aerobic) or VO2Max (High Aerobic)?
Although, some coaches espouse the same approach and only consider training effect per session, not based on time-in-zone, and get fussy when athletes combine different intensities in one session. So, if all your sessions each strictly target one specific intensity, Garmin’s approach is probably fine.
follow up question:
I had an event on my calendar (and an associated training plan, that I paused at some point), and the “low aerobic shortage” fell on the base perdiod garmin suggested in preparation for the event.
could that effect the volume requirements for the different effort buckets?
edit: I deleted the event from my calendar. now my watch says my load focus is “balanced”. garmin connect (web and mobile app) still says my focus is “low aerobic shortage” in the “in focus” tab, and “balanced” in the glance.
Most definitely! Future events on your calendar (as long as their Training Priority is set to either Primary Event or Supporting Event) affect your Daily Suggested Workout for that event’s sport (if it’s cycling or running) and overall Load Focus bucket targets. So, the Load Focus allocation if you have a planned marathon in a year from now will be different than if you have a 5K two months away.
Connect and the device can lag against one another when it comes to many of these ‘Unified training status’ features, as some of the calculations happen on the device itself and need multiple syncs to become reflected in Connect.
That all makes sense (even if not accurate, as you say), but then when I go to the gym for weightlifting, Garmin insists the workout was mostly aerobic.
The only thing I can think of is that a set (3 working weight sets of 5 reps) takes less than a minute, then I rest/pant for 3-5 minutes. Thus most of my workout by time is spent resting with a Low Aerobic heart rate, not actually lifting. Silly Garmin.
I noticed that tendency as well! A lot of it comes from the ‘smoothing’ by the optical HR sensor’s error correction algorithms – from personal experience, when a wear a chest strap for an intense strength / resistance session, the HR peaks and valleys are much, much more pronounced, to the point where I can immediately see each working set and its rest period on the HR chart. Sometimes that’s even enough to make Garmin think I was doing intervals.
Strength. I tend to include a warmup ride on a stationary bike at the gym, so there’s generally also a whopping 2-mile Indoor Bike session in the same multisession workout.
Usually, when I encounter inquiries of this theme there is at least one of 3 variables that the trainee got wrong or inaccurate:
Exercising consistently within prescribed zone.
Knowing the zone limits.
Actual zone definitions (Garmin or you got the zones incorrect)
As for low Aerobic, data has shown that:
Zone 1 is “garbage” zone with very low benefits and very time consuming.
If your zone 2 is correct and you never go above or below…the best benefits come from its lower half.
Most amateurs don’t do zone 2 correctly and tend to stray above it at different frequencies which are pricy as far as the physiological systems are concerned.
My advice is:
Reset the zones.
Do your own zone tests.
Concentrate on discipline regarding not leaving zone designated.
There isn’t much confusing about that really. No coach worth his salt, or athlete with even basic knowledge of training, would suggest that Z2 and Z2 only is the holy grail. What I did find interesting is the Intervals strategy for harder efforts…keep something in reserve. Sound advice if ever I’ve heard it.
At this point, we’re off on a bit of a tangent – the OP’s question was very specific – but…
I don’t think what Olav said here (and earlier in Peter Attia’s long-form podcast) at all contradicts the existing wisdom and what Iñigo San Millán has been saying for a decade, it’s just GCN in their normal fashion sensationalizing his words with a clickbaitey title and soundbite questions.
Can you do only Z2 and get quite good? Yes. Can you win Tour de France on that? Like Olav explicitly said in the intro – no. But I don’t think 99% of people watching that video are trying to.
He was also very astute in pointing out that many people in the 6-8 hrs/wk training cohort tend to underestimate the intensity and end up one gear above what they actually intended to target while also often neglecting to listen to their body. But at this kind of low volume, going a bit higher on intensity is not necessarily bad – as long as the athlete can sustainably absorb it long-term.
If memory serves, Iñigo San Millán, in his GCN interview, said that Z2 should be about 80% of training, not 100%.
I agree with the last two replies - there’s no contradiction, confusion or disagreement, only a sensational video title.
Also, my original question was answered perfectly, so feel free to go on tangents
I had an extended (over about 9 months) conversation with various Garmin support people about this. At times it got a little heated.
They first told me my zones were set wrong. I showed them they were set according to some broadly accepted standards and that even sticking within these zones didn’t correlate with the activity class. I was then told it ignored my zones and used FirstBeat’s zones based on HRmax. Nobody seemed to know how it actually worked.
I showed them a large number of rides that were miscategorised, with some great solid zone 2 efforts with low cardiac drift, mostly zone 2 power and HR which were classed as tempo. Quite a few big threshold sessions (3 hours) which were classed as vo2max or anaerobic.
Fundamentally, the way Garmin categorises activities is completely proprietary and isn’t shared. They wont change is despite repeated demonstrations that it’s inconsistent and illogical. I’ve just learned to ignore it now, as frustrating as that is.
That’s quite common these days. Big companies buy up part of or entire smaller companies to actually buy ‘installed base’/market share. But often the engineers/developers don’t come over or quit soon after the merge, and knowledge is lost… They just keep selling without knowledge
I have to disagree with you on that. Yesterday, I ran an 11 km LIT/Zone 2, and for every km, I incorporated ~6 seconds of maximum effort intervals (alactacid anaerobic). The load was correctly recorded by Garmin as both “Light Aerobic” and “Anaerobic” accordingly. (Both load values increased after the activity)
The Watch/Garmin Connect does show only one “main benefit/Load Focus” but in the background, it is accounted into the different areas (Light Aerobic, High Aerobic, Anaerobic).
