Hi,
I recently did a lactate test and got my LT1 and LT2 (among a few other values and zone recommendations.)
I know I could change my cycling power zones (and did already), but im not sure, what to set as my FTP? As far as I know, TSS is based on FTP.
Should I set my LT2 as FTP? Should I do a 20min FTP Test to get my FTP? (Which seems weird to do, as I have a more accurate lactate test…) If I set LT2 as my FTP is my TSS wrongly calculated?
Thx in advance, Jan
If all is well, power @ LT2 should be very close to FTP, close enough to get good TSS numbers.
And if you set power @ LT1 as the top of Z2, the Seiler zones will also be close enough.
Just remember that a lactate test is a snap shot in time, as is the 20-min FTP test. You will have daily variations on both tests.
To compare your lactate test, you would have to repeat it under similar conditions, to see improvements, just like you would with a 20-min test.
I would still do a 20-min test, but 105% of the LT2 number, and see if I could (1) get to 20-min, and (2) extend the duration for as long as I could if I make it to 20-mins and feel good. The 20-min effort must however include the 5-min all out effort before the 20-min test.
Thx for your answers.
My problem is: I’m pretty sure I can maintain 300+ Watts for about 20 min (after the 5min all out) which would result in 285W FTP. My current LT2/MLSS was measured at 267W (and its reasonable, because it’s not my first test)
So: 18W between those two - Is it close enough for a reasonable TSS?
There’s some more recent studies to show that 90% is more accurate than 95%, and 300W *0.9 is 270W: Relationship Between the Critical Power Test and a 20-min Functional Threshold Power Test in Cycling - PubMed
It depends.
MLSS is not the same as FTP from a 20-min test (less whatever %). Even a MLSS test cannot tell you exact MLSS value as the step increase is 5-10W depending on the weight of the athlete.
The 20-30 minute FTP is done as maximum, which means you are often above threshold, which means you aren’t in a steady state.
That would be close enough…
I was tested with a INSCYD protocol, not a ramp test. But nevertheless 5-10W is accurate enough for me.
But:
On friday my brother did also a lactate test. He also did a 20min FTP test (including a 5min all out) a few weeks ago. He could manage 290W for the 20min, so FTP is somewhere between 261W (90%) or 275W (95%).
His MLSS was measured at 235W, which is quiet low according to the 20min test values, BUT he has a very high vLamax of 0.62 mmol/l/s (VO2max is 53,12 ml/min/kg). That’s why he could held high power for a shorter period of time I assume.
I know from expirience, if it goes any longer he would drastically explode. If he went on longer climbs he intuitivly falls back to around 240W so I would say the lactate test seems correct.
So my initial questions remains, not for me, but for my brother: What should he set his FTP at in intervals.icu to get correct TSS Values?
What are you using TSS for? CTL/ATL/TSB? Unless you are an elite training at the edge of limits, you might be surprised how poorly you can estimate FTP and still get reasonable results from the PMC.
In other words, the PMC might still offer fair to good guidance without high TSS accuracy.
Use your INSCYD values.
