What is FTP? The FTP (Functional Threshold Power) concept has been around as long as we have known about the lactate turnpoint, or the intensity at which out body produces more lactate than it can clear. The figure above is from a book published in 1979 by Dr. David Costill. The data is from a paper published in the 60s. However, FTP is a relatively recent term, but is simply another name for LACTATE THRESHOLD (Note, there are LOTS of terms exercise physiologist use to describe this like VT2, lactate turn point, anaerobic threshold, etc… It’s that “FTP” has simply caught on with cyclists).
The FTP concept takes the “threshold” concept and brands it specifically to bike power (and now run power). FTP is a POWER (wattage) value that correlates to the point at which you have accumulated a given amount of lactate in the blood, and if the intensity is increased, an unsustainable amount of lactate will accumulate and you will fatigue quickly. If the intensity is decreased, the amount of lactate will decrease and you can exercise for a long time. Kind of like a balancing point- more intensity and you tip the balance to unsustainability – you fatigue and have to stop working. Less intensity and you “recover” and can keep working.
This physiologic value has been measured for decades in the lab and in the field. It has only been in recent years that marketing and the need to drive revenue for products (power meters, books, training platforms, etc.) has made FTP popular in the cycling world (and now running world?!?!? ). It’s also a way for relatively non-educated ‘coaches’ to sound like they know what they are talking about.
So, what’s my take on FTP?
There exists a sweet spot, I call it “the edge,” that represents an intensity at which you are producing the most amount of lactate you can sustain so you can exercise for a required duration. And this “edge” varies depending on the duration of your event. For example, if you are running the 800 meters, you are able to handle really high lactate levels (because the race is over in under 2 minutes). For longer events, you need to keep your lactate levels under a certain level in order to sustain your desired pace.
Typically, the general thought is that FTP is the power you can sustain for 40-50 minutes. You know you are at this “FTP effort” because it hurts. It hurts the entire time. It hurts from 5 minutes into this type of effort until you finish. So, FTP is where you burn, but you can sustain the burn.
The funny thing about your lactate threshold is that it varies from day to day, and it changes throughout a season. So, when you hear people clinging to a training plan that requires that they ride at their FTP, you are potentially over-working or under-working on any given day.
Ignoring “FTP,” simply understanding how much power you can produce for any given duration is important so you understand how to pace yourself. FTP simply estimates the power you can hold for 40-50 minutes.
BUT… some events are shorter, like a 20k TT, and some events are longer, like an Ironman triathlon.
So, how does FTP influence racing? Or a better question is how does FTP influence the type of TRAINING you need?!
Taking by itself, FTP gives you very little insight into your physiology. But taken as a part of a spectrum of variables, FTP can be a nice metric to monitor fitness changes.
My opinion (short version): FTP as a ‘gadget’ will lose its luster as more and more devices dumb down science for the athlete. However, the concepts and science behind APPLICATION of FTP (or simply threshold) can never be ignored IF they are taken as part of a scope of important fitness data.
FTP can provide valuable data that allows us to quantify work and measure change in performance. However, it can also be a limiter if you use FTP as the end-all be-all metric of fitness.
My perspective is that FTP is an important metric, but needs to be evaluated within the greater scope of your physiology. I will expand more on this concept in future posts.
RUNNERS NOTE: the FTP concept is taking the running world over too. It uses the same principles as cycling, except these are applied for running. I think power for running is BS, but we shall see how technology innovators can quantify work without actually measuring it.