[Nick D’Hulster]

Hello, hoping to gain a bit of insight into this:

I’ve used my lactate monitor many, many times so I can get a good sample and keep consistency as far as the testing procedure goes. I recently did an informal test during 2x 15 min on x 5 min off Zone 3 (tempo) intervals. Started the test at 1.2mm/mmol of lactate and slowly rolled into a faster pace and HR (155bpm just at AET) @ 20 mins. I normally read 2.0-2.2 mm/mmol at that pace/hr.

1st interval was sitting at 158-160 HR so for me mid Z3. Lactate 5.2 mm/mmol. Re-tested 15 secs later and 5.1 mm/mmol.

2nd interval sat at 160-162 HR. Lactate 5.5 and 5.2.

After 5 mins cooldown HR was back to 128 and lactate was 1.8.

My question is I’ve done so many field tests and a couple lab tests so I’m pretty tuned into what my zones are, breathing and effort wise I was certainly not above my threshold during these intervals. So why would my lactate be sitting at 5 when I can roll at 155bpm for 1.5 hrs and be sitting right at 2.2-2.2?

 

AET 152-155 during an easy week and

Ant 167-168- Lactate tested at 4.0-4.2

 

I’d assume tempo I’d be right around 3.0-3.8 or so.

I’ll note I did hit the sugar water during the workout to fuel but don’t think that would spike the blood lactate so high.

I’m not overtrained or super fatigued either, just coming off a big volume summer of mostly z1-z2 15-20hr weeks and transitioning to sprinkling intensity in for the Skimo season. I recovered just fine from this workout.

Any feedback is greatly appreciated, I really just would prefer to not target above threshold training until about another month from now. Thanks!

[Nick D’Hulster]

Update: Did another set today of 2x20min @30%incline. Had pretty low resting lactate this morning at 0.8. Tried to get a better warmup and sit at the target the last 3 mins of the warmup. Lactate read 2.9 @ 158 so perfect. After the first 20mins tested at 3.7 and 161- slightly high but still good. 2nd 20 min interval same exact pace with a slightly lower hr at 158 and lactate at 3.2. I figure I kicked the shuttle off after the 1st interval and so got lower lactate for the that reason.
This was a perfect test as far as the training I wanted to get. I guess I’ll do the exact same workout for this block until I want another adaptation. What’s odd though is I did the same warmup last week and had the incline at 20% as opposed to 30%. Only wrench in the system would be last week I just got back from a 2 week trip near sea level and had returned to 1500m elevation about 5 days before.
Again thank you for any insight or feedback!

[Scott Johnston]

Nick;

Very interesting dilemma you are presenting us with.  I can’t say with any certainty why your lactates were so high in the first test.  You have thought of all the factors that might have influenced it:  A stay at sea level and a sugar water drink during the test could both impact the reading.  Another could have been dehydration.  Since we are measuring the concentration of lactate mMol/liter of plasma volume, if plasma volume drops due to dehydration, lactate levels will be higher.

Hopefully, all your subsequent tests will be more like the second one you just performed.

Scott

[Nick D’Hulster]

Thank you Scott. Dehydration hopefully is the answer. Otherwise maybe I have diabetes hah! I’ll post another if the readings are strange.

One take away I’ve come to learn is personally whether odd readings or not it takes 6-10 mins for my lactate and HR to coincide accurately. Shame when you go to a lab they just keep bumping you up 2-3 mins at a time.

[Dr Andy Reed]

In our lab, we prefer longer stages in the aerobically fit, so that we get a better handle on your HR. I use a minimum of 4 min stages in the ultra athlete, for the very reasons you describe.

In terms of your lactate testing, I agree with Scott – I suspect the drink +/- dydration would explain it. One other quick thought – we did have a batch of out of date test strips that gave some anomalous readings a while back – maybe just check the expiry dates. Likely not that but an easy check.

Andy

[Dr Andy Reed]

In our lab, we prefer longer stages in the aerobically fit, so that we get a better handle on your HR. I use a minimum of 4 min stages in the ultra athlete, for the very reasons you describe.

In terms of your lactate testing, I agree with Scott – I suspect the drink +/- dydration would explain it. One other quick thought – we did have a batch of out of date test strips that gave some anomalous readings a while back – maybe just check the expiry dates. Likely not that but an easy check.

Andy

[Nick D’Hulster]

Unfortunately I’ve learned the expensive way that most labs don’t think like you.

[Author]

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