[Nick D’Hulster]

Hi, I can’t seem to find much info on the nitty gritty of self testing with a meter outside of a lab so figured I’d ask here.

I have a Lactate Plus meter. I’m wondering after finishing a nice steady 5-8min interval how long will you get an accurate lactate reading? Say you’re skiing so you pause, drop poles, remove glove and pull out meter from crampon pouch. Probably 15 secs. Then add another 20 secs to prick finger wipe blood and finally get the sample. My HR obviously has dropped about 20 beats by this point but how long will your lactate levels be stable at that original interval HR? Especially if you get a bad reading and have to redo.

Thank you for any response!

[Scott Johnston]

Nick:

It depends on the intensity you were at when you stopped.  If you are into the red zone  (Z4) there is a good chance that your lactate will continue to rise for at least a couple of minutes (if not several) after you stop exercising. That’s because there is a transit time from the muscle cell to the blood.   The diffusion of the lactate across the cell wall depends on the shuttle proteins of course but alto on the difference in lactate concentration across the cell wall.  If there is a lot of lactate to be shuttled the blood concentration will continue to rise for minutes post exercise.  To prove this to yourself take a sample at 2min, 5min and 8min post very intense exercise and you will see lactate level climb and peak at maybe 5 minutes and decline after. The faster that decline the more aerobically adapted the athlete.

For more moderate intensities the best you can do is to be consistent in the timing.  A minute is about the fastest you are going to get this process accomplished.  With that consistency you will at least be comparing apples to apples.  You can take some comfort in the fact that the lower lactate gradient across the cell wall the slower the drop will be.  But everyone is going to be somewhat different. At least with the lactate plus you only have to wait 13 seconds to find out you messed up and need to test.  If you don’t get a good sample on the second poke don’t try again or you will end up adding another minute on tot he testing (with all the fiddling around).

It’s an imperfect science. Just try to make it a bit less imperfect.

Scot

 

 

[Nick D’Hulster]

Thank you Scott, nice and thorough! The high intensity post-rise was also what Kylee had told me. I guess it’s quite a niche tool for laypeople that they don’t give to much info in the How to Test Manual. I had a good difference recently in a field test vs a lab test after doing a very gradual warm-up instead of the lab spike but there was a slight 45sec delay on skis. It did read exactly where I expected though 152 bpm@ 1.9 vs the labs 150-155@ 3.0. Basically everything I’ve tested in the lab both times have had quite skewed results vs field tests. I’ll have to upload the 2 gas exchange tests here as an example of funky results because of warm up or fueling poorly.
Thank you again

[Scott Johnston]

Nick:

I’m glad that info helped.  The only reason I can figure that most labs don’t allow enough gradual warm up time is that they are trying to maximize the $/hour they get from the tests.  I would hope they understand well enough that the aerobic metabolism takes many minutes to come to full capacity and if you rush it with too fast a ramp rate or too short of a warm up you will miss the lower threshold.

I also prefer field tests to lab tests. Especially if you have a lactate meter.

Keep up the good work!   This stuff is not rocket science and just understanding a few basics will get a long way.

Scott

[phillip.hare]

Nick,

It sounds like you already have a good procedure down in the field, especially if you’re conducting spot checks at different intensities. However, I’ve found some information from Gordo Byrn, a triathlete/coach, quite useful in terms of how to self test. This video, and maybe parts of this one as well.  Gordo definitely advocates for long warmup protocols and longer steps during a ramp test.

[Author]

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