Nice test!
I also have been using Dfa-a1 for a few years now for cycling and running and it works out quite nicely for me. The data point lines up with my lactate testing and RPE. But I use 0.8 as my threshold since it fits my numbers better and 0.75 is an upper bound based on a data set.
Retested and not quite sure what to make of the results when compared to the two previous tests.
If I plot out HR alone, it’s apparent fitness has improved. Lower HR for same efforts.
However, things get interesting when I plot out LT values over previous tests.
NOTE: It’s clear the 9th value at 6:22 pace / 9.4 mph is invalid.
Also, It’s now even more obvious the January test values were impacted by not following the exact same protocol used in December. (TLDR: I skipped earlier stages in the January test)
My takeaway is my LT1 improved from test to test however my LT2 readings are unclear to me.
LT1
December 139 BMP @ 7:53 min/mi
January 138 BMP @ 7:35 min/mi
March 139 BMP @ 7:03 min/mi
LT2
December 155 BMP @ 6:49 min/mi
January 152 BMP @ 6:49 min/mi
March 148 BMP @ 6:35 min/mi
For reference, here are the graphs for the three tests.
Any/all feedback and observations are welcomed. TIA
LT2 is always unclear. It’s not actually clear to me that LT2 even exists. MLSS exists, but that is a different test. Take home - don’t worry about LT2 from these sorts of lactate test protocols.
Looking at your heart rate and the slight change in lactate concentration from 8:34 pace to 7:03 pace between the December test and the March test, I would conclude that your training program is having a positive effect.
LT1 in March looks to be shifted to just under 7:00 pace which is nice work indeed.
I would keep doing what you are doing. Your endurance running efforts (eg HR and Lactate at slower than 6:20 min pace) looks to be coming down and that should be a sign of building fitness. When you turn to speed work or race prep should be in good shape. Am sure you can feel that with RPE and general sensations when running below race pace.
Is that a typo in your tabulations for LT1 and LT2 in terms of months? Should it be December - January - March and not December - January- December?
I appreciate the response… I’m going into the final block for London and was hoping the results would be a bit different (better?) but such is training. Will take the results to help inform the last few weeks to prepare as best as I can.
Its also great to take a step back view how things have progressed even if we don’t always feel it in the day to day.
You’re right, typo. Fixed.
That probably sums up every athlete’s view toward their training and results!! It’s a good sign to never be content 
December to March probably isn’t long enough to see a change in “threshold” power or running pace. If you are already in good shape, and have trained for a relatively long period, it becomes very difficult to move threshold up and see a change. RPE and HR at that effort or lower look to be heading in the right direction so I would be pleased with that result and feel good heading into the event.
My experience when training well is that while my FTP didn’t bump up much, with good training diligence I could still improve other metrics and improve race day performance.
What I see with solid training is that my RPE and HR at threshold decrease noticeably and my TTE at MLSS goes up. In lactate step-testing, at sub-LT1 levels I’d see a solid 1.1 - 1.3 mMol and the LT1 point would keep moving closer and closer to MLSS. For MLSS testing, things stayed about the same in terms of lactate concentration, but it became easier to ride at MLSS (RPE and HR). RPE being a qualitative mental measurement and HR being quantitative and physiological.
I’m suggesting that you are seeing something similar. Your race pace (surrogate for MLSS) might not be improving drastically, but you are likely feeling that race pace is easier. If you’ve been doing endurance training for a full marathon, that is a great result and should point to a good race day.
Good luck with London Marathon and hope it goes well.
Thank you - I appreciate the insight and perspective. We all easily get hyper focused on one thing or metric and lose sight of the bigger picture.
Other than that I think for amateurs, whose overall range is much smaller, better to do 20w steps max, not sure.
Why did you only provide numbers up to 200w? What were the readings for 225, 250, and 275?
Nice graphs. Good work. Do you mind sharing your google sheets/excel file?
Thanks. It’s quite basic but sure.
Thanks!
I’ll share mine once I’ve made adjustments to suit my protocol
I have read through the article and would like to try it out on my partner. Which device is the best/gold standard for home use?
Typically for home testers in the USA market the choice has been the Lactate Scout or the Lactate Plus devices. The vendor Lactate.com sells both along with test strips and other supplies.
These devices, or prior iterations, have been tested and there are some academic publications characterizing the performance of the devices. The two brands above were both fine for home use.
I’ve recently seen ads for a device called EDGE Blood Lactate Monitoring System. There is discussion of this device on Reddit. I have no experience with this device.
For home use, I’d pick a brand of test device where I can ensure a supply of test strips. The brands that have been around for a while also are easiest to get supplies for.
For lancets, you don’t need anything special. I suggest single use disposable lancets with a retractable needle. I typically purchase the McKesson brand safety lancet. It is useful to keep a few different gauge lancets on hand. Some days you need a bigger needle to get a good drop of blood.
Probably the biggest variable for home testing is getting a good blood drop and a non-contaminated sample. There are instructions up thread on how various people do this. As a self-tester, I finger prick myself and have a protocol that works. Earlobes work if you are testing someone else.
Have fun and post results to share.
Darth