First Ventilatory Threshold and Fitness

if you need some more background about the science behind FTP I can only recommend you listen to this episode discussing it

Ross isn’t just an excellent scientist but also an avid cyclist (albeit not a Sufferlandrian). always worth listening to


@Jim :- I think some SUF workouts are certainly targeted at extending your time to exhaustion at FTP. E.g., Thin Air/It Seemed Like Thin Air, The Wretched, Team Scream, even Hell Hath No fury. The workouts mentioned on the Empirical Cycling podcast that include even more time at FTP are pretty advanced by SUF standards, and in fact by anyone’s standards. E.g., Phil Gaimon talks about the threshold workouts he used as a pro on his YouTube channel, and he said that three by 20 minute workouts (mentioned by Empirical Cycling) were tough even for World Tour riders!


@Heretic I guess the only truly accurate measure of FTP will be a blood lactate test! Although I wouldn’t be surprised if clever analysis of heart-rate variability might become a viable option for pinpointing both aerobic and anaerobic thresholds in the future.

@Coach.Suzie.S Thanks very much for your thoughts and input!

As you say, I do suspect that for most people simple endurance volume will do the job of providing the desired aerobic adaptations. That said, I may follow your advice and do some self-experimentation during the build phase of next season. Instead of solely doing rides that adhere to the advice in the “Endurance+” workout, I’ll throw in some lengthy “top-end endurance” intervals early on in the progression and see how that works out. Keeping a close eye on heart rate and breathing patterns should make it fairly easy to stay out of the tempo zone.

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Cool, I’d love to see a report back on your experience with it!

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That is the reason I have come around to the view (as outlined in the article link) that the best measure of FTP is the level at which I can ride moderately hard for the longest amount of time.

I do not have access to a lab, and a one time test would not be helpful, so blood lactate testing is not an option.

This is also why the 20 minute test is not a good one for FTP, some people have a large anaerobic component at that time, and some do not. This is where TTE at a given power level comes in to play.

The FTP measures in 4DP and Half Monty are still useful because all we need are consistent measures to judge performance improvement. It does mean that if you doing ride planning you may not be able to rely on an FTP test.

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I have found that the workouts you mentioned do seem to increase my TTE at FTP.

Since I have done all four FTP Progressions in the SUF program with little difficulty, I am starting to do longer ones. I did 3x15 yesterday at 95% FTP. I made it through, although the last interval, especially the last 5 minutes of it was tough. I probably will repeat that until I feel comfortable, and then move to 2x20.

Remember as well that the Empirical Cylcing podcast also says that many people’s FTP numbers are too high. If you have trouble with those intervals even at 95% of FTP that is probably the case. The reason for the higher numbers and the difficulty is that your test number probably includes a significant anaerobic contribution.


Since my reply where I relate my experiences with SUF FTP Progressions and FTP. I did the FTP Building Block and it seemed to help.

There is a SUF FTP Progression at 4x10 which the Empirical Cycling Podcast suggests is the starting point for FTP/TTE work.

The reason that you could hold your FTP for only 40 minutes is probably because there is an anaerobic contribution to your 20 minute test results. Here is an article written by one of the contributors to the Empirical Cycling Podcast that discusses this issue:

Hi all,

I was reading through this entire thread. So much great information and science. I have a question that some of you might be able to help me with.

I had Vo2 max tested at a sports science lab. My Vo2 max was fine. It was 48, which is 114% predicted. Nothing amazing, but I have been ill and haven’t worked out like I used to. I’ve had unexplained shortness of breath. No doc had been able to tell me what’s wrong.

What I noticed from my CPET test is that my VT1 was 44% of my Vo2 max.

Have you seen number that low? Any clue what this indicates? I thought normal VT1 was much higher than that. Am I overly concerned about this or can VT1 indicate something important about my breathlessness with exertion? Is VT1 very improveable?

Any thoughts would mean a lot!