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Lactate Threshold during a Track session is much slower than rep speed

chunkywizard
over 6 years ago

One for I think.

I got my first Lactate Threshold reading on the 945 at track tonight. Not sure I believe it though. I did 12x 400m with a static rest. The 400s were ok done around 1:22 which is about 3:25/km pace. The L/T was reported at 4:11/km 155bpm! 

I don’t understand if all reps were done at that pace how an L/T threshold 40s/km slower is recorded

is this to be expected?

CW

  • 0 over 6 years ago in reply to johann.fuehrer

    Surprising accurate OHR (I had a strap on but it didn't connect and this morning I swapped out the battery to fix it)

  • 0 over 6 years ago in reply to chunkywizard

    But the 945 can estimate lactate threshold also with optical heart rate? In the guided test it requires a chest strap and the test doesn't start without chest strap.

  • 0 over 6 years ago in reply to 5571286

    I’d have to check it definitely was OHR, as I say I was wearing a strap, but I’d had it not connect a couple of times. I think you can investigate the fit file to find the HR source, can’t you?

  • 0 over 6 years ago in reply to chunkywizard

    The analysis required to provide your LT can only be performed using data captured by a paired chest-belt. That didn't change with the introduction of the FR945. So, something is a bit strange here. 

  • 0 over 6 years ago in reply to Fredderic

    Yes, based on the initial post/question, I also think there is a bit of confusion about what LT is and what it means. gave a good serviceable laymen's accounting of LT, saying that it's about the sustainability of efforts. Basically above that level of effort/pace, the sustainability of your effort drops off a table. 

    How does your Garmin watch actually do it? Here's a good source.  

    https://www.firstbeat.com/en/consumer-feature/lactate-threshold/

  • 0 over 6 years ago in reply to HermanB

    thanks for the reply. I know what LT is but my question was more, how could it be calculated from a 12x 400m session where I was either stationary or anaerobic. From the article you linked to "To calculate your Lactate Threshold, the Firstbeat analytics engine requires a stable VO2max estimate and enough quality heartbeat data recorded across a range of different intensities from low to high. This data can be gathered during a guided test specifically designed to record the data needed to detect your Lactate Threshold, or it can be calculated from normal running activities that include enough quality heartbeat data from each zone."

    I don't know how this session had enough quality heartbeat data from each zone.The heart rate data is basically saw-toothed, to it goes to Z4/5 very quickly into the rep then when stationary slowly decreases to Z2, then back up to Z4/5 quickly, 12 times. None of the run was at or around the threshold pace.

    Is it just magic? And do you consider the LT given for this session to be accurate?

  • 0 over 6 years ago in reply to chunkywizard

    As Clark's 3rd law states: "Any sufficiently advanced technology is indistinguishable from magic." 

    So, yes, it might be magic. And, thank you!  :-) 

    I'm kidding, of course, but if you look at the image on the right side of that page, you'll notice that the LT detection point is a deflection in the HRV plot. This is recognizable as your HR increases from bellow the LT to above it. It's not about 'staying at' your LT, but rather passing through it that makes the detection possible.

    Is the LT you managed to have detected during your interval runs accurate?

    Well, I honestly have no idea. - but ceterus paribus "4:11/km 155bpm" does sound reasonable given a cursory understanding of everything else you've said. 

  • 0 over 6 years ago in reply to HermanB

    Thanks for the explanation!