Endurance Nation | Online Triathlon Coaching & Community

Voice of the Nation

LT vs FTP Watts

My replies to a thread in a forum:

Snip………

Poster (not Rich): Thanks Mike, I appreciate your information. I was given a Lactate Threshold Power number of 250 watts. This was performed by a high profile coach and ex-USPS team member who you would know. Would the FTP number be based on a similair test as the 40min TT?

Rich: What Mike is saying is that most of the power-users in the tri-world speak in the terms provided through WKO+. Functional Threshold Power (FTP) is the baseline number we use to make sense of all the other numbers. FTP = the power you can hold for a 60′ time trial. The 2 x 20′ (2′) that jaretj referenced above is a “good enough” test, as few of us are able to make a quality 60′ TT happen very often.

There are other methods but what is important is that they are a measurement of what you can DO, not what your blood chemistry, gas exchange, whatever says is going inside your body. Think “I can bench 250 lb” vs “I breath into a tube/get my finger pricked while I’m on the bench. SmartGuy sez that at chemistry/gas marker X I have 250lb on the bar.”

Sounds like you are using the later and depending on the test, the tester, definitions, etc, it’s possible for you to have a wide range of results. But the rest of the power-training tri-world is speaking from the perspective of “I don’t really care what’s going inside my body. All I know is I can bench 250lb and that’s the number I use as a frame of reference.”

————————

“Rich, I really like this analogy. I get so frustrated by athletes I know that pray to the all powerful lactate scout. Have you ever written an article expanding on this theme? If so, please share the link.

A question regarding FTP vs power at LT. I have seen determination of aerobic threshold based on LT as being -15 to -20. Is there an accepted factor for determining aerobic threshold off of FTP”

————————

Rich: Lots of stuff in the free ebooks below:
Endurance Nation Long Course Training Manual, aka, The Book
Out-Season Training Guide
Heart-Rate Training Redefined
Training with Power ebook coming out next week, also free, will include $20 off this Training and Racing with Power Webinar

I don’t work with aerobic threshold. I think like this:

  • Establish FTP
  • Work at percentages of FTP to achieve certain adaptations:
    • To lift FTP (get faster), do intervals at 95-100% of FTP
    • To rack up a lot of TSS/hr (train time-efficiently), ride at 80-85% a lot. This is also HIM specific intensity, roughly
    • To focus on IM specific stuff (intensity, positional adaptation, and generally get good at all the stuff you’ll do in an IM bike), ride at 68-75% of FTP.

These go into a training mix and think of it as the ingredient slidersorwhatever on the Infinit site. Depending on where you are in the season, time avaiable to train, how close you are to your race, you move these sliders left or right.

I’m not very concerned with what’s going on in the body. Focus on what you can do, express everything as a percentage of what you can do, and if you want to get better at a thing, do that thing. Life, not a spreadsheet, dictates how much time you have to do a thing.

-End Post-

Many power atheltes out there are working within an FTP framework but have also been tested to determine lactate threshold…hopefully watts at lactate threshold. What are your observations about the differences between the two?

Interested in joining our team of over 400 long course athletes? Learn more but hurry, the doors close to new members on May 1!

Popularity: 23% [?]

Training
  • Joseph Elmer
    Great post, well written!,
  • Thoughts from Steve Cramer, from inside the EN Forum:

    For once, Rich, you've managed to see a ST hell-thread before me! The new job is interfering in my forum-related activities!

    Without having read the thread in question, my understanding (from years of listening to smart guys like AC, Rich, etc.) is as follows:

    * LT describes a purely physiological phenomenon (the point at which lactate accumulates in the bloodstream). It has no direct relationship to performance in exercise.
    * FTP describes a functional (i.e., related to performance) benchmark, specifically the average power an athlete can sustain for an hour's maximal effort. It has been shown to correlate well with LT, but it does not itself describe any physiological phenomenon.
    * We base our training efforts off of FTP because of its basis in performance (as AC says, "the best predictor of performance is performance itself"), and because it has been shown to correlate well to LT.
    * LT as a benchmark is cumbersome to measure at best (and any attempt at MEASURING LT without taking blood is not measuring at all, but just getting a swag).
    * Anyway, it's not specifically LT you'd be after, anyway, but the external measurement to quantify it, such as HR at LT, pace at LT, or power at LT.

    So, can you structure a training plan effectively with something like power at LT in hand? Of course you can, but unless you've got a lab in your basement and the stomach to bear periodic LT testing protocols, sticking with the de facto standard of FTP is just a helluva lot easier, not to mention the fact that if you're using power, it's what nearly everyone speaks anyway (well, everyone not desperately trying to apply yesterday's terminology and principles to today's technology and understanding of physiology).

    cramer
  • admin
    @ All - the problem I have with lab testing, even when you can do it with a PM and extract watts from the test, is that it introduces another variable into the test: the test itself :-) My this, I mean the device, the protocol, the tester, etc. I know I can one athlete with the same PM to three testers and get three versions of "your watts at LT are X," even if all three testers are using the same device.

    For FTP testing, there is no variable. Just go that way, as fast as you can, until the clock sez stop. Done. No device, not tester, no interpretation of results...just ride.

    Rich
  • cutiger95
    Mike,

    I would agree, as an engineer at heart and in production there are three things that a measurement gage must have, only two of these apply to an athlete in training.

    1) Repeatability
    2) Accuracy
    3) Discrimination (ability to see changes)

    The two that are going into my search for a gage are Repeatability and Discrimination. In reality I could care less if my watts/lb are x or z. Only that my watts/lb are increasing.

    If I were a betting man and betting on races then I dang well would be interested in the accuracy so that I could put the money on the right horse per say. Otherwise accuracy only applies in the bar at the end of the ride. And guess what it won't matter at that point as everyone will already know who the strongest rider is and was at that time.

    So what are your true watts does it really matter?
  • Mike
    I'd go one step further, Rich. It doesn't even matter how many watts you're actually pushing. As long as your measurement system is repeatable, and you see improvement over time, then you're going in the right direction. You've probably never picked up a 45lb plate at the gym and walked over to the scale with it. For all you know, it weighs 43lb. Doesn't matter, if this week, that's all you can lift 10x, but next week, you can do that plus a plate labeled 5lb 10x. Accuracy in this game, while interesting, is largely irrelevant for the athlete who's self confident enough to not need to compare their numbers to another athlete...
blog comments powered by Disqus