@lactate_boi Thanks for clarifying and further elaborating! I figured it was the 200m or 400m repeats you were referring to but it’s interesting and noteworthy that even for a MLSS test, below MLSS, you typically see a drop in the reading after the first test point too.
@_vance With regard to your question, I don’t know how you’d target a lactate level without a meter? I’ve played around with taking my lactate curve and plugging the speeds that generate different lactate values into Daniels VO2 formula to see at what percent of VO2Max do those values occur and if they are consistent with others lactate data. There appears just too much variation for my taste to suggest matching paces to lactate levels that way though, in general.
Duration plays a role in lactate too, especially when faster than your MLSS. Olbrecht has a plot (for running) that shows the lactate variation above MLSS when using 3, 5, or 7 minute intervals. While VO2 is stable for all three durations, lactate varies significantly. Conversely, Olbrecht also has a plot (for swimming) of a 6*200m w/ 30 sec recovery where the lactate drops successively with each repeat (from 4.0 mmol to 2.5 mmol), for a workout done at a pace just slightly faster (I believe 102% V4, compared to 99% V4 for the 400m, where V4 is velocity at 4.0 mmol). Point being, you can achieve whatever you want really, it just depends on the execution.
As an additional point, part of the reason the initial lactate is higher and then settles (or even drops) when the pace is constant, is the aerobic-anaerobic energy contribution due to the minimal recovery. On the first repeat, you’re starting from rest, so the initial ~1.5-2 minutes is being supplied “anaerobically” while each successive repeat is being started at a higher level of rest due to the incomplete recovery thereafter, thus requiring a lower percent of “anaerobic” contribution. So, how long your aerobic system takes to “ramp up” is dependent on the workout structure.