Are FTP test really that important?

Based on my last reel that I posted about my FTP test, I realized from the comments that for some reason, people put a lot more emphasis and importance into these tests as they should. It’s some kind of cultic thing that people pursue, and for some reason, they have these weird, arbitrary standards that they hold on to.

So today, I would just like to clear up all this mess and show you how you should really perceive FTP tests, what do they tell you and what they don´t, based on my experience as a coach, rider, and racer.

The first question we need to answer: What actually is an FTP test? In power-based cycling training, we always need to establish a set of personalized training zones, which we will later use for structuring workouts. In order to be able to calculate these zones, we need some kind of baseline. The FTP or “functional threshold power” is the most commonly used one of such baselines. Varying different definitions exist for this term, but broadly speaking, we consider it to be the maximum average power that you are able to produce for a long, steady, sustained effort of 40 – 60 minutes. This is purely the physical aspect of it though, as the physiological side is slightly more complicated and often debated. In short, it is a measure of the maximum aerobic ability of a rider.

How can you find your FTP?

Assuming you own a power measuring device, such as an on-bike direct force power meter or a smart indoor trainer/indoor bike, you are able to approximate your FTP in home conditions using various types of performance tests. The two most commonly used ones are the “Ramp test” and the “20 minute max test“. The ramp test can only be effectively performed in a controlled indoor environment using ERG Mode.

What is ERG Mode?

When ERG mode is activated, the indoor trainer or bike will force the rider to hold a prescribed power. Since the rider always has free control of the cadence, the device does it by manipulating the resistance. Power equals torque x cadence. If the rider tries to overshoot the set power, the trainer will decrease the resistance so power stays the same. In case the output of the rider is lagging, the resistance will be increased so the power level is still the same even with the lowered cadence. Failing to keep up, this will trigger a so called “spiral of death”, where the resistance will increase so much that the rider can no longer turn the pedals over. This kind of control is necessary for a ramp test to be effectively performed.

What does a Ramp test look like?

The standard protocol has a 100-watt starting point. From there on, the required power will be increased by 20 watts each minute until you can’t pedal anymore and hit the death spiral as previously mentioned.

This type of exercise to failure is caused by the ever increasing lactate concentration in the blood of the rider performing the test. The algorithm then uses the strongest 1 minute interval of the test to approximate the breaking point in the lactate curve and thus your theoretical second lactate threshold, or in other words, your FTP.

Pros and Cons of the Ramp test

Due to the nature of the test, no pacing strategy or any other thought is required, which makes it suitable for beginners (who have no previous experience or approximation of their fitness level), or riders who are coming back after a longer break from training. Just like with any test however, the result will be greatly influenced by the rider´s ability to push themselves and suffer. Freshness and the mental state will also play a big part, as it is a maximum intensity, painful effort.

The main downside also stems from this feature. The test protocol is anaerobically biased, meaning that it will overvalue the ability of riders with a strong anaerobic engine. Conversely, it punishes riders with above average aerobic power. This skewing of results is the main reason why I do not recommend it to advanced level riders, based on power only – metabolic testing will also be needed to optimize results.

Due to the conditions described above, it is not possible to perform such test in outdoor conditions and without the correct equipment – making for another potential downside as most riders cannot perform at their best indoors.

The test protocol is also strict about performing the test as a fully seated effort. The main purpose of this is to not disrupt the ERG mode of the trainer – standing up and changing the cadence/resistance dramatically can skew the results. It might also be seen as a way to keep the lactate increase steady and to not interfere with the calculation, as it relies on the steps and the last/strongest 1min of the effort.

As an addition, Zwift now also offer a modified protocol called “ramp test light”, which starts off at 50 Watts and goes up in increments of 10 Watts per minute. This test is much more suitable to beginners, considering that most of them fall somewhere between 1.5-2.5W/kg in terms of FTP. Young riders or females weighing 40-50kg would not get far past the 100W starting point of the regular test, making it hard to achieve an accurate result.

Pros and Cons of the 20 minute max test

The other popular way of testing for FTP is the 20 minute max power test. In my mind this is the more advanced option, as it produces more accurate results for most riders. It is worth keeping in mind though that this is still only an approximation. The only 100% accurate way to test FTP would be to do an actual 60 minute power test. In practice, this is rarely the case though, as it is both impractical and extremely demanding for the rider.

The 20 minute version is a practical substitute, as it is much easier to find a suitable place to perform a 20 minute uninterrupted maximal effort. Not to mention the fact that it is also much less demanding both physically and mentally, so it can be performed with greater regularity when needed. The goal for the test is brutally simple – the rider has to generate the highest possible average power for the duration of the test. Based on the resulting number, first the FTP, then the training zones will be calculated.

How is your FTP calculated?

The common practice is to take 95 percent of this average power for 20 minutes as the FTP. In practice, the real FTP can deviate based on the strengths and weaknesses of the rider. For riders that are strong aerobically, such as myself, it can easily be more than 95 percent. A good example of that would be an Ironman relay that I have done last year, when I have averaged 295W for 2 hours with a theoretical FTP of 310W. That is a very small discrepancy making for an extremely flat power curve.

Anaerobically adept riders will have a much more pronounced power curve and might find to apply the 95% rule for their FTP. The same can be the case for novice riders, who are generally not as good at pushing themselves (and/or pace incorrectly) during a long steady effort. In these cases, it is often a good idea to apply a lower percentage, such as 92% for example. Despite this complication, I still believe that it is the more accurate type of the test.

On the upside, it can be done outside without any external help, just by using an on-bike power meter. The main difficulty of course is the proper pacing of such effort, which certainly needs some previous experience and a base line where you can start off.

Speaking of the pacing, the best result will always come from flat pacing, or a slight negative split. Ideally, the rider should completely empty the tank by the end of the effort, to get as close as possible to the theoretical maximum power. This will also mean using the last anaerobic reserve and pedal out of the saddle for the last part of the test.

Conclusion

Performing a high quality test of either type will undoubtedly be beneficial for any rider`s training. However, these results should purely be perceived as part of the training process. They are not really an achievement in themselves and there is no need to be overly focused on the outcome, as there are many other factors that will determine a rider`s success in real racing.

While the test result certainly does offer some insight into the general ability of a rider, it is never the complete picture. Other factors such as endurance, repeatability of efforts, ability to clear lactate, race strategy, fueling etc. can be just as important. Not to mention the ability to produce power in different ways over different durations. For this reason, we also tend to complement FTP tests with other power profile tests to get a clear idea about the strengths and weaknesses of each rider.

The most important takeaway is that cycling fitness is a multifaceted affair and should not be judged on a single metric. If you are and avid rider looking to improve your performance, check out our individual coaching service here.