Fatmaxxer will work with a H9, the only difference is that you will not get an ecg file.
Iād be a little surprised if you remained above 0.75 in the tempo zone, possible I suppose but seems unlikely for a prolonged period.
be surprised 
And Iām far from alone from reading these threads.
Obviously there is drift over time, but I tested with 6 and 8 min interval steps and it was pretty clear where I went <0.75, on several tests with different apps. Iām tempted to try a couple of longer indoor rides with Fatmaxxer and see how long it takes for the DFA1 to drift.
I should also add Iāve been a high volume rider for ~12 years, with 100,000 KM outdoors just on Strava already and loads of time spent in z2 endurance work for many years. Before that I also ran and swam quite a lot as well. I guess I have a fairly well developed aerobic system really.
Lol, sounds fair enough when you describe yourself like that.
Hope that didnt come across as douchey,ā¦ but I rode for years with olā skool club riders and weād ride 80-100 mile weekend club rides on a bottle of water, a banana and a coffee half way around. You did NOT want to be the guy that pulled a gel out of their pocket or decided theyād hammer up a hill before April
Canāt deny these old boys are probably still the fittest riders Iāve ever ridden with. Most did have 30-40+ years in their legs though!
No it definitely didnāt, as you say, having a massive endurance base makes things like DFA alpha1 more reliable as a source of effort monitoring, Iām very envious.
I tried HRV Logger and was doing 10w increments and after 6 or 7 DFA alpha 1 went a bit bellow 0.75 but i continued and it went aboveā¦
Do I need to use first value as LT1 or the value where DFA alpha 1 stabilised?
How long was each step? They should be 6-8 mins so values stabilise. Otherwise Iām not really sure as all my tests have been pretty easy to interpret and I havenāt seen this issue Iām afraid.
6min. after third measurment I increased power
Use this link (posted already earlier by @enki42) for calculations or if youāre into programming, hereās extracted python script. It takes HRV Logger generated CSV file with RR values as input and prints HR
2 Likes
Same here. My test (have to do it again) gave 145bpm and 220W, that is in my Z3 zone (low Z). But I will re-do my test this week.
Interesting thread indeed. In my shorter endurance rides, maybe I focus more on time just below LT1. But for longer endurance (3h+) I will try to ride around 185-200W. Still base period soā¦
Bruce Rodgers has said in his blog somewhere that 0.75 is an average of where LT1 falls, some people might find it at 0.8 say.
Ran DFA Alpha1 analysis on a lot of data over the last two years, and ended up at around 142bpm and 81% HRmax / 89% LTHR. Right at the top of my Friel Zone2-HR and about the middle of Coggan Zone3-HR.
Also, the data for inside workouts collected using Garmin 530 and Dual HRM is super clean with few if any artifacts.
Same here based on DFA alpha1, however I have no lactate data to collaborate those results.
Using percentage of FTP (which is usually based on another percentage) to deterimante zones is practical and fine for a lot of people but for some is not even closeā¦ I did a lot of lactate testing and ride analises and found that is not strange to find upper zone two to be for example 260w and FTP to be 290wā¦
On the other hand I currently have an athlete who cannot hold 170w without big HR drift but doing 4m intervals at 420wā¦
2 Likes
My last lactate test was end 2019 (every 3min +40w). But I think it overerstimated my LT1.
0
10min 100 1,36w/kg 110bpm 0,8mmol/L
13min 140 1,90w/kg 120bpm 0,5mmol/L
16min 180w 2,45w/kg 128bpm 0,5mmol/L
19min 220w 2,99w/kg 149bpm 1,0mmol/L
22min 260w 3,54w/kg 164bpm 2,6mmol/L
25min 300w 4,08w/kg 174bpm 9,5mmol/L
28min 340w 4,63w/kg 178bpm 10,5mmol/L (peak at 178W and 313W)
It stated my LT1 at 160bpm and 255W and my LT2 at 170bpm and 280W. So that seems very high. 280W is around my FTP but that 255W. I donāt know if it is correct. But maybe with some good testing for the dfa A1 maybe I can get a clearer result. And I am now fitter then in 2019, certainly my endurace as normally have increased to because did more volume in 2021 en 2022.
Do you use Runanalyze for analysing your files? Or what software do you use?
Having done some lactate testing myself this sounds like a recipe for inaccurate results. Also I wouldnāt necessarily think that results from a lactate test over 2 years ago are still valid.
Step duration was too short and power increments too big.
I use 5-7min for step duration and 20-25w increments.
There are a lot of methods but I found that you should look the curve and then find best method. Usually is around about 1mmol above lowest reading (not rest value)
You should be well warmed up and not be eating at least while doing the test (but I would suggest even 2hr before)
Yep - I use 6min steps, with (depending in athlete) 15-25W increments (sometimes confirmed with a MLSS test, but rarely).
The Colab notebook and similar code on my laptop. Every indoor and outdoor ride is recorded on Garmin 530 and dual HRM.
Interestingā¦seeing these big individual ranges makes it even harder to make sense of oneās own data interpretationā¦
Did you have any quick recommendations for those 2 showcases given above?
(Like more intensive/raising the roof work for number 1 and more long slow steady state endurance for number 2.)