Ed-
Yes, the lactate curve is the primary driver of "threshold" determination. However, other factors can "nudge" that up or down.
I can see why that particular threshold was chosen (it corresponds to an inflection point / non-linear rise / a rise of 1mmol followed by 1.5 or greater on the subsequent stage. (
Edited to remove incorrect labeling of "Coyle Method").
My arm wouldn't have to be twisted very hard to nudge it up. Personally, I always used the modified Dmax method. I've found it works well, but is a bit difficult to understand. Additionally, It's likely that I would have had you do another stage, but again, I can understand why you were stopped where you were as we typically looked for lactates >8.0mmol/L prior to ending the test and 7.9 is very close.
To play devil's advocate on the prior posting: IF the oxygen sensor were reading high, that would explain the increased Caloric expenditure, but would also have lowered the RER and I do not see that being the case. Thus the CO2 sensor would have to be a bit off as well and I really do not see both of them being off.
Therefore, I feel the raw data that you received is accurate. There will always be slight variation in interpretation between individuals. However, in this case, the end results are equivocal.
Case in point: I tend to define the upper end of my threshold zone (4) with the threshold pace, whereas this tester tends to increase threshold zone above the threshold pace. At the end of the day, both my interpretation of Zone 4 and theirs are essentially the same number and therefore the practical take away is the same. But, my "Threshold" pace would have made you feel better ;). I'd also say the same about Zone 2 as well. Frankly those are the two most important values to take away from a test like that. Anything over threshold, frankly, ought to just be $%#@ hard!
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