Another "Zone 5" Thread - Why is this possible?

Like the name says, its a "zone"! 
Staying in Z5 for 40mins doesnt mean you are on max sprint effort. You can well be in the base of zone5, so the algorythm wont understand its impossible for a human being. 

Like said, best way to calculate Z5 is using LTHR. The lactate threshold is the point where you change from aerobic to anaerobic, acumulating lactate, what is unsustainable.

But if you are just above LTHR (Z5 base), the lactate will accumulate slowly. Also when you reduce your pace to below LTHR you body eliminates some lactate (rest) so that you can increase your pace again, back to zone5. You can see this clearly in the new Stamina datafield/gauge.

9970217 said:

Like the name says, its a "zone"! 
Staying in Z5 for 40mins doesnt mean you are on max sprint effort. You can well be in the base of zone5, so the algorythm wont understand its impossible for a human being. 

Exactly my point.  It's a zone with a range, and there are different zone classifications for a reason.

But I disagree on the second statement.  If someone is in the base of Zone 5 (5.2 in this case) or really anywhere in Zone 5 for 40 contiguous minutes, then by definition it is NOT Zone 5.  I know that, you know that.  Unless of course we change the definition of Zone 5.

And Zone 5.0 is still Zone 5.  If you go for a run and the watch auto analyzes that you were steadily running Zone 5.0 for 30 continuous minutes, then hey, either the world needs to change Zone 5 definition... or maybe, I need to bump this guy into zone 4.9 instead of 5.0.

I don't know how to improve the default auto-detect algorithm; that's the job of the developers. But I know it is possible.   These are not all black and white static equations.  Do you know how Firstbeat Analytics "recognizes" LT?  An isolated deflection in HR variability.  There are tons of algorithms, complicated if/then scenarios, etc. running under the covers.  They are updated and tweaked over time.  I'm suggesting that there is room for improvement here.

I wanted to mention that most high end Garmin watches have auto-detection of LTHR and there is even a dedicated guided LTHR test. But you have to wear a chest HR sensor. 

I get your point. 

But what you are questioning is the concept of 5 zones in the running world. Yes, there is room for improvement. Yes, there could be 10, 20 or 50 HR zones. But I guess it would made it even more complicated for the average user. 

When we read online descriptions of what zone 5 means, its usually a very resumed explanation. So maybe what is wrong is what you are assuming by the "definition" of Z5 when you assume it is a quick sprint. A sprint is inside Z5, but it doenst mean all of Z5 is a short sprint effort. So it's not that we need to change de definition of zone5, but probably describe it better. But the average user will prob get bored and stop reading when he sees that big and technical text lol.

The fact that you get very tired after spending 40min on zone5 only confirms you were on zone5. If you were on zone 4 you should feel like you could keep going for a whole marathon, like 4h~5h continuously. Compared to a 40k run, a 5k run can be considered a "long sprint", while a 200m run in max heart rate will be a short sprint. The difference is how quickly the body accumulates lactate and reachs exaustion. 

Finally, about the algorythm. Yes, there is always room for improvement. But AI is still a long way to go in all aspects before it can replace human interpretation. Specially for a very data driven guy like you (and me). So it is up to us to fine tune the user definition and feed the Garmin algorythm the best we can. When you fine tune your HR zones, a few more BPM in the Zone5 starting point will probably make much difference when you are running around the edge between Z4 and Z5 like was the case.

9970217 said:

The fact that you get very tired after spending 40min on zone5 only confirms you were on zone5. If you were on zone 4 you should feel like you could keep going for a whole marathon, like 4h~5h continuously.

Thanks a lot for your writeup.  On this point, though, 100% of Zone 5 characterizations I have read say differently:

Garmin:
"Sprinting pace, unsustainable for long period of time, labored breathing"

Polar.com:
"Your maximal effort. Your heart and your blood and respiratory system will be working at their maximal capacity. Lactic acid will build up in your blood and after a few minutes you won’t be able to continue at this intensity."

REI.com;
"This maximum speed zone (think closing kick in a race) trains the neuromuscular system—your body learns how to recruit additional muscle fibers and how to fire muscles more effectively."

TheAthleteBlog.com:
"short intervals, up to 40 seconds.
Zone 5 is the ‘all-out’ effort – the maximum what muscles can produce. At this intensity massive amounts of lactic acid are produced and it’s impossible to utilize it. Muscles get so tight that an athlete is forced to slow down."

marathonhandbook.com:
"Zone 5 is where you are running at your absolute maximum effort! This means you will be unable to work at this intensity for more than a few minutes."

9970217 said:

Finally, about the algorythm. Yes, there is always room for improvement. But AI is still a long way to go in all aspects before it can replace human interpretation. Specially for a very data driven guy like you (and me)

I'm getting there!  I used to be anti-gadgets and tech, then a little over 3 years ago, I started tracking my activities (mostly runs and Crossfit WODS).  Now, I am trying to analyze all this awesome data to try and improve my performance in a smarter manner.  So I do have a learning curve and also could be expecting too much of the current software capability.

Thanks for everyone's comments.

It doesn't matter what oversimplified summary you can find that is not the definition of zone 5. The start of zone 5 is your LTHR. If you are fit, you can hold that for about an hour. Do you know what the upper end is? Well, there really isn't. It's just your max. How about instead of looking for an oversimplified explanation you read about LT?

Also if all your runs are zone 5 either your LTHR is wrong or you are running too hard all the time which will lead you overtraining, a plateau, or injury

NickAtkins said:

It doesn't matter what oversimplified summary you can find that is not the definition of zone 5. The start of zone 5 is your LTHR. If you are fit, you can hold that for about an hour. Do you know what the upper end is? Well, there really isn't. It's just your max. How about instead of looking for an oversimplified explanation you read about LT?

Also if all your runs are zone 5 either your LTHR is wrong or you are running too hard all the time which will lead you overtraining, a plateau, or injury

Thanks.

In this work, Joel Friel divides Zone 5 in three:  Zone 5a, Zone 5b, Zone 5c. 

joefrieltraining.com/.../

9970217 said:

In this work, Joel Friel divides Zone 5 in three:  Zone 5a, Zone 5b, Zone 5c

Thank you, I have bookmarked his website!  Looks like a great resource.  I may even pick up the Total Heart Rate Training book.

Yes, the 5a/5b/5c would closely align with the Garmin %LTHR zones, which puts "Maximum (Zone 5 )" as "99-110%" of LTHR, rather than % of Max HR.

From the above, you HR zones are based on HR max. Sounds to me like the watch is underestimating you HR max as you do not achieve it during your activities. Try sprinting as hard as you can at the end of your 50 min "Zone 5" session and see where your HR max ends up.