Lactate Threshold and Max Heartrate Problems

Sometimes I find that these anomalies are symptoms of the many layers of updates combined with the complex configuration options in these devices.

i tend to change settings, save and then revert back again to ensure they take effect. I would turn the auto detects off, save and or sync, then lower your max hr manually before turning them back on again. You’ll prob find that’s enough to fix the issues. It may be worth going through and refreshing other settings in the same way.

Hey. Older watch manuals, but I think it’s safe to assume this quotes are accurate based off your experience:

NOTE: The device detects a maximum heart rate only when your heart rate is higher than the value set in your user profile.

which can be a problem for LTHR tests for the reasons you described:

Also, do you wear the HRM every time? It seems the apps are both designed to rely heavily on regular/repeated use to calculate things. 

https://www8.garmin.com/manuals/webhelp/forerunner245/EN-US/GUID-F7949BD6-8AC9-4015-8D63-E5F085E55279.html

www8.garmin.com/.../GUID-1B0C9B93-01CD-4A0C-A30F-B815C0347159.html

dizzzy said:

Hey. Older watch manuals, but I think it’s safe to assume this quotes are accurate based off your experience:

NOTE: The device detects a maximum heart rate only when your heart rate is higher than the value set in your user profile.

Yeah, I quoted that in other comments and I don't think it is true any longer for recent watches. Now, the Max HR algorithm can propose an Max HR value even if your last activity peak HR is below it, and the proposed Max HR can be below the peak HR (if the watch didn't see the peak HR as "qualified", I guess).

tropicaljones said:

Each attempt has failed as I can't get my heart rate above the 150s. My max heartrate (also on auto-detection) is down as 203bpm

As dizzzy suggested, the LT HR is influenced by the HR Max as the watch is looking for specific trends around 90% of HR Max.

tropicaljones said:

I've run a 2:43 marathon (6:12/mil, ave HR 152) and a 1:18 half (5:58/mil, ave HR 140) in the past year and would have thought either of these would be sufficient for my watch to auto-detect that a lactate of 7:09/mi is wrong

Well no, the watch will propose an auto-detection if your heart rate vs pace meets certain trend criteria.

Here is what I recommend:

- if you are a trained runner and your doctor lets you, run you best 5k ever with a chest strap. Take the peak HR (typically towards the end) and add 5bpm. Put this as your Max HR.

- then, run the lactate threshold built-in test. If it works, you should have a LT HR close to 90% of your HR Max.

- enable Max HR auto-detection if you want, but think twice before accepting the changes. Your Max HR will decrease slowly with age, but it will also decrease if you train a lot vs a non-trained individual. No pressing need to update the Max HR more than once a year.

- you can enable LT auto-detection but again, take the proposed updates with a critical eye. If your workout is not reflecting a progressive increase in HR, the results might be wrong. When I do anaerobic or VO2 Max intervals, I get a new value, and it is almost always wrong: LT HR too high and pace too slow (probably due to the mix of run/rest efforts).

Three things,

1) My 955 has detected a lower Max than what was set twice in the last week. The first was after a very easy run and Max was lowered by 1 bpm. I went in the settings and changed it back but the very next day, on another very easy run, it lowered it back by 1 bpm. I have now decided to just leave it. 

2) On both these occasions I was not offered the option to reject the new Max. 

3) When you do get a new Max detected, check your zone %s. For some reason Garmin takes it upon themselves to change them when a new Max is detected. 

burns3 said:

When you do get a new Max detected, check your zone %s. For some reason Garmin takes it upon themselves to change them when a new Max is detected

i have noticed this. The zones seem to stay the same even if they’re set to %maxHR or LTHR and those values are updated. 

I usually just hit the “reset to defaults” button

This manually lowering max hr and lthr before doing a LT testrun, helped me out in the past. After that, switched off autodetect. Good zones after that.

I am having a lot of MaxHR issues myself these days. 60 YO male with a 955S I have had for a couple years. I was immediately drawn to your post as my maxHR consistently gets reset to 203!!! I have turned off autodetect for MaxHR and it still gets updated. I thought is was related to auto software updates so I turned that off and only do those manually. It still happened overnight last night. My best guess at maxHR from runs and from other sources like Orangetheory tell me 174, which really seems like the right number. So I reset to that one often. Similiar to your description there is no workout that shows a 203 value in my history.

paulshepherdjr said:

It still happened overnight last night.

It is weird that you get an auto-update overnight. Typically, a new auto-detection happens only after a workout as you save it. You should look on Garmin Connect, in your user profile to see what value you have there, update if necessary and see if these overnight updates still happen. If they do, you should contact Garmin support

paulshepherdjr said:

My best guess at maxHR from runs and from other sources like Orangetheory tell me 174, which really seems like the right number.

It might be. Be sure not to confuse Max HR and Peak HR. It is unlikely you get to Max HR during any workout. Typically, your muscles are giving up before the heart get there. It is possible to get close to Max HR during a controlled test and/or certain conditions (see post above).

Make sure you wear a chest strap. The wrist HR will give you spurrious data that can throw the detection algorithm off.

Heck, even with a chest strap I got a wrong detection a few days ago: I replaced the strap (straps typically last between 9 and 12 months in my case before they start creating issues).

When you start running, with any HR sensor, monitor your HR, in particular during warm up. You can also set up an HR alert for any value that gets close to your estimated Max.

It is weird and yet I woke up this AM with a maxHR setting of 203 after going to bed last night with a maxHR setting of 174. No workout. Watch on my wrist all night. No software update as I have turned off auto update for software. I’ve started looking each night before sleep and when I wake up. Mainly because if your day starts with the wrong maxHR, all of the training effects and classifications for your exercises are screwed up and cannot be “unscrewed”.

paulshepherdjr said:

I woke up this AM with a maxHR setting of 203 after going to bed last night with a maxHR setting of 174.

I suppose there is a value in Garmin Connect that get synched to the watch. Try to correct the value through the web interface.