Calculating your FTP is unnecessary for being in the right zone

Knowing your FTP, or at least a decent approximation, can be helpful for some things. In particular, it’s helpful for calculating TSS .

However, it’s totally unnecessary for being in the right training zones when doing intervals, and may actually be very counter productive. Lately, I’ve been simply tracking my interval workouts, and to progressively overload, I increase either the duration or the wattage.

So, if I’m doing a 4 x 6-minute interval workout, and doing the best I can (i.e. the most watts to successfully complete all 4 intervals), then I know I’m in the VO2max zone since the duration is in the 3 to 8 minute window. When I repeat that workout, I should be able to increase something - either duration (e.g. 6.5 minutes) or watts.

An advantage of this approach is it takes into consideration your unique power profile i.e. whether you’re a sprinter, time trialist, all arounder, or whatever. Maybe your anaerobic intervals (30 seconds to 3 minutes) need to be higher or lower than your FTP would indicate. By tracking your intervals, it just doesn’t matter what your FTP is, you simply want to progressively overload in some way.

I do occasionally test so that my TSS is reasonably accurate, but in reality, I could get a good approximation based on the IF of the interval workouts I successfully complete.


You’re talking about working to RPE. Working with power is more precise and more reproducible.


Counter productive? I disagree.

I’ve trained the way you describe, and I’ve trained with TR plans. Both will result in gains, however the TR approach has produced the quickest results with the least amount of effort.

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How on earth did you think I’m referring about working to RPE when I mentioned “watts” ? I’m definitely referring to power.

I’m confused about your remark, there’s no reason you can’t use a TR plan with this approach. Have you never increased or decreased the percent for a workout?

I misunderstood you initially as well.

You’re talking about training with power, just not functional threshold power in particular.

And instead of tailoring a sprint effort to FTP, the sprint effort is tailored to itself, for example.

Is this what you’re saying?


There’s nothing earth shattering here which is why I’m surprised by the initial comments :slight_smile: Zones are only approximated by a percentage of your FTP. In reality, the various energy systems are stressed differently depending on the duration of the effort i.e. completing a 1-minute interval workout at the highest power you can muster will be an anaerobic workout, and completing a 6-minute interval workout at the highest power you can muster will be a VO2max workout regardless of what you think your FTP is.

FTP works great for the majority of people, especially for longer duration intervals such as threshold intervals. But some people can do a given anaerobic interval workout at 160% where another rider may only be able to do the same workout at 130%, etc.


My confusion is that you started the thread saying FTP is “totally unnecessary” and may be “very counter productive” - and then did not appear to substantiate or prove either point.

Thats ok, just trying to understand. Its hard to follow, if I understand it seems you are saying something else in your reply to me.

How about this - do you agree there is value in using FTP to establish zones, and then during a workout modify specific intervals based on feeling and/or your own physiology and response to the effort?

If that is what you meant then I agree. And I’ve heard the exact same thing said on the podcast. There have been several podcasts where Coach Chad talks about focusing on increasing the capacity to do the work, even if that means modifying ftp or increasing/decreasing % during particular intervals.

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So while not talking about RPE, the difficulty that arises becomes pacing and is exacerbated the longer you go. Do I need to know what my FTP is to do 20-min interval repeats that are challenging? I don’t. Over the course of ten years training with a power meter, I know what I can do when I’m rested, or when I’m coming off the couch, or when I’m tired. I know that generally, I can dial in XXX watts at the start and get through the interval, then repeat it. That comes with experience.

To people who haven’t ridden with power that long, it becomes more difficult for a lot of the same reasons the 20-min FTP test is hard for many, not for others: pacing. You’re going to get better training benefit out of something that is challenging but doesn’t bury you until the end of the interval, and then repeating that, than you are by jumping into an interval fresh, then watching your power slowly fade until you can’t hold a target power any longer. I futzed around training that way for years before I started paying real attention to FTP, perceived effort, and target power zones. That type of training is, in my experience, less effective than specific, targeted training that is repeatable and doesn’t cause undo fatigue because you don’t know how to properly pace for one reason or another.


The concept is both simple and well established.

Point 1: FTP is unnecessary to train in the correct zones:

I’ll use a concrete example. If you successfully complete a 4 x 6-minute workout with the highest power level you can (e.g. each interval is of the same power, and the power is even throughout the interval), that is a fantastic VO2max workout. This can be done without ever testing your FTP. Hence, FTP is not necessary for training in the VO2max zone. What is necessary is using hard efforts of 3 to 8 minutes in length.

Point 2: Using FTP may be counter productive:

By training in this way, your Anaerobic, VO2max, Threshold workouts can vary independently according to what you can physically do. Using FTP to set the zone would limit your anaerobic workouts to 121% to 150%, but maybe you can do a 3-minute interval workout using 155%. Limiting yourself to 150% would be counter productive.

I think you have misunderstood my point. There is no pacing issue with what I’m describing. I agree that if someone is starting from scratch w/ power, it would be much simpler to take an initial FTP test to get in the right ballpark, certainly. But once you’ve been doing a set of workouts for a while, it becomes very clear what your limits are, then it’s time to either increase watts for the workout, or increase the duration of the intervals, while still staying in the zone.

So you complete a 4 x 6-minute workout at 270 watts and felt like you still had something left in the tank. Well, next time, either try it at 275 or 280 watts, or increase the interval duration to 6.5 minutes, etc. i.e. progressively overload.

I really had no idea this would be such a difficult concept to understand :slight_smile:

These points practically contradict each other.

The first point, I agree with as I said above - for riders experienced with working with power and who are in touch with their capabilities relative to their place in training, how tired they are, etc.

The second point I don’t agree with. This is the entire point of periodic FTP testing. If the only thing you ever care about training is VO2 and Sprint, then yes, I agree with that. You’d be better off just winging it day to day and see improvements as you redline yourself each time. Most - most - cycling events have large aerobic components, so generally we all want to train our aerobic engines. VO2 is part of that. As VO2 capabilities improve, your FTP is also usually going to improve, and I’d bet that the Ramp Test would particularly bear this out since it probably has a larger potential VO2 component than a standard 20 min Coggan test does.

The other thing I’d argue against it being “counterproductive” is that when you advance your training - say you’re able to conduct those intervals at 155% for the first time - your body may need additional rest to recover from that and come back adapted and ready for the next training session. Part of the benefit of testing FTP -> training by zones defined by FTP -> retesting FTP -> repeat… is that it is a measured approach that will give results that are close to the best you could possibly do while also reducing instance of injury, burnout, overtraining, or simply excessive fatigue. Most seriously competitive people are far more likely to overcook themselves than go too easy… the old adage that most athletes fail to train easy on their easy days and hard enough on their hard days. FTP provides a simple, easy to use metric around which to plan more effective training than simply going out and hoping you’re going to hit that higher power this time around.

TL;DR: what you’re espousing is probably “perfect” if executed perfectly, which is probably extremely difficult to do… don’t let perfect become the enemy of good enough.


It’s not. What I’m getting at is if you progressively retest your FTP, say every 6 weeks, you’re probably going to be doing that anyway.

You’re also introducing uncertainty… you could finish those intervals at 270 feeling great one day, and say “I’m going to come back and try for 280!” but because of fueling, sleep, stress, any number of other factors, you can’t hit that number, and now instead of steady intervals at 270, you start out at 280 and finish at 260 because you can’t maintain it. That’s also sub-optimal training, and what I was driving at with the comments about pacing.

Most TR plans that I’ve looked at progressively load you anyway, by either increasing the power demand or increasing the interval time and/or decreasing rest. Could you do that on your own? Of course! But most people aren’t going to do that very well on their own. It’s really, really hard to be objective about your own training.

You’re still not getting it.

Consider two riders. Rider A and Rider B. They both happen to have identical FTP values.

However, rider A is full of fast twitch muscle fibers, and rider B loves time trialing. It’s very possible that they need to be using different power levels for their 1-minute interval workouts despite having identical FTP values.

I hope that clarifies it. If not, please refer to the Allen and Coggan book and look up “power profiles”

I’ve read the book several times. I understand what you’re saying, and basically spelled out what I thought in the post above this one.

Rehashing: For someone who cares only about VO2 and sprinting, what you’re talking about is probably true - they’d be better off training that strength at powers irrespective of their FTP based on their known capabilities in those power zones. But most riders take part in events that require training their aerobic engines to a greater extent, therefore for most people, FTP is going to give them the best results, or at least results close enough to the best possible results while eliminating room for making mistakes in planning and executing their training.

Most riders - and probably all triathletes - spend the vast, vast majority of their training time training their aerobic capabilities and racing primarily on the strength of their aerobic capabilities, which means training with FTP is the best route for them to go. That may not be true for a track sprinter, for example, who would be unnecessarily limiting themselves as you’ve pointed out.

This is making the 4DP argument. Which doesn’t say FTP is bad, just that you need more numbers. Which may be true but would lead to having to test more or more complicated/less reproducible testing.

Coggin zones work for most people. The people that it isn’t good enough for know who they are.


Except that’s the opposite of what I’m saying :slight_smile: In other words, you don’t have to test more to do this. You just have to track your workouts with respect to power & duration of intervals.

Now I totally get that many/most people don’t want to track their workouts in this way, but doing so means you don’t need to do a 4DP test. So it’s not accurate to say this would require more and more complicated testing.

I’m not going to disagree with your example in point 1, however I feel like you are ignoring all phases of the base/build/speciality training model. What is your example for base training, when I only have a limited amount of time (say 6-8 hours a week)?

Its not difficult to understand, and I definitely know where you are coming from. Three years ago I trained for the DeathRide without power and without knowledge of FTP. Majority of training was on the flats, with several 1 hour threshold intervals each week along with other rides with shorter intervals. This was using the Strava/CTS plans with only RPE and heart rate. I’m a big guy, and was able to finish all 5 passes and 15,000’ of climbing by mostly training on flat ground and doing 1 hour threshold intervals.

Then my second year I trained with power and Strava/CTS plans. This past year I’ve been training with TR and power, and have obtained quicker gains, with less overall training stress.

So while “unnecessary” (isn’t most technology?!) for targeted efforts like a 1 hour climb, I’d rather train smarter by using FTP to establish zones, follow structured workouts, modify as needed, and achieve the same result in less time.

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Am I the only one totally confused by this? Is the OP basically saying… “you don’t need a threshold to train smart with power, and you’ll actually be better off just training to power”?

But… if I just got a power meter, without finding an FTP or setting training zones around that FTP, how the hell do I know what power to train at on any given day?

When I first started training with power and TR, the first thing I noticed was how much harder they were telling me to go on intervals than I was previously riding. eg: “Holy shit, this workout is telling me to ride at 300 watts for 3 minutes straight 10 times repeatedly! I never would have done that before”

So in summary, you’re suggesting I set my power zones based on “I think this is as hard as I can go” versus automated Coach Chad taking my FTP in TR and prescribing “this is how hard you NEED to go to improve”?

In short, he’s saying that using FTP could unnecessarily limit your higher-end power training unnecessarily because some athletes are more conditioned to fast-twitch, high power efforts than others. While VO2 intervals are typically done between 120-150% of FTP, some riders may be able to regularly train VO2 type intervals at 155% of their FTP, for example, because of their specific make up, and thus the standard FTP zones might limit the effectiveness of their training. Basically, their aerobic fitness lags their anaerobic fitness.

I think he’s probably right for a very small subset of riders - maybe track sprinters, for example. But a lot of the people for whom training by their FTP might be suboptimal, they probably aren’t training by it anyway, and don’t pay a whole lot of attention to a power meter in real time. For the other probably 99% of us who ride primarily aerobically (with some bursts of sprint or VO2 level effort), training by FTP is the best way to go, IMO.