Power-based training is without a doubt the best way to structure training for cycling. However, if your FTP isn’t accurate you could be missing out on the benefits of training with power.


Training with Power Explained

Power-based structured interval training is one of the most accessible and accurate ways to measure performance for cyclists. With a power meter, you’re able to precisely measure how much work is required of your body at any given second of your ride.

The crux of power-based training is a benchmark called FTP, which stands for Functional Threshold Power. This acronym represents a close-enough representation of your lactate threshold in terms of power and is a benchmark used to scale every interval to your specific needs. That way, you can be sure that you’re training at exactly the right intensity at all times.

However, if your FTP is not accurate, then you’re essentially using a ruler that appears normal, but has incorrect inch measurements.

Reasons Your FTP Could be Inaccurate

Your FTP is assessed through a structured test that should push you to exhaustion. If you are training regularly, you should reassess every 4-6 weeks. While training, as more time passes between testing, it’s highly probable you’ve gotten stronger and that your FTP from your previous test is now too low.

Interestingly enough, your effort in a testing interval is a maximal effort, so while testing above your limits during that interval is fundamentally impossible, there are a couple of exceptions. Firstly, if you your last FTP test was taken while you were at your peak, and you’ve since taken time off, that FTP will likely be too high for your current fitness. A more common scenario is one where a rider is doing a workout that contrasts to their current abilities. For example, if a long-distance triathlete is trying to complete a neuromuscular sprint workout, chances are they will feel their FTP is too high. The same would be true for a cyclocross racer trying to complete a 30-minute threshold interval. In this case, their FTP could be accurate, but they are asking their body to work in a way that is completely foreign.

All that being said, it is certainly possible to under-assess your potential. When riders enter a test already fatigued from a previous day’s training, hold back, lose focus or pace incorrectly, they are sure to alter their results.

FTP testing is a skill in itself — every rider experiences a learning curve as they reassess every 4-6 weeks. With that in mind, new riders can safely assume that their FTP from their early assessments may be close, but not spot on. That’s not necessarily a bad thing at first.

Since new riders are exploring their limits and familiarizing themselves with riding at those limits, their “actual FTP” may differ from their “performable FTP”. This decoupling is resolved quickly with increased familiarity to training, and there are a number of signs to look for that indicate your FTP is too low.

Signs of a Low FTP

Rest intervals are too easy

This is the most common problem for cyclists who are new to power-based training. Due to inexperience, their FTP is low and it is noticed in subsequent super-tempo interval workouts. If your workout has you training at or above sweet spot, you should be looking forward to your rest intervals and need to take them easy in order to be ready for the next work interval.

When riders can ride well above the indicated power during a rest interval, they’re either hampering their recovery for the next interval or seeing further evidence that their FTP was underestimated. But in too many cases, the rider goes from working a little too hard during the recovery interval and not hard enough during the work interval.

If this is the case, try bumping the intensity of the workout 2-3% and see if those rest intervals transform from a bore to a godsend.

Over-under intervals aren’t exhausting

These type of interval workouts have you working just below threshold for a period of time before going just above threshold. This pattern repeats any given number of times during each interval set.

Over-unders are known for being very challenging both mentally and physically. The reason for this is because your body is forced to exceed its lactate processing limits and recover just below those limits. Mental and physical triggers cry out for full rest in order to recover, but you are teaching your body to recover while still working hard.

After each “over”, you should feel a burning or flooded sensation in your muscles and be out of breath. If you don’t feel these sensations, it’s a good sign that the “over” portion of your intervals aren’t truly over your threshold. Try increasing the intensity 2-3%.

Long threshold intervals are too easy

Certain workouts will have you riding at threshold for extended periods of time with little rest. For example, Lamarck‘s four threshold intervals are 10 minutes long with only two minutes rest in between. This workout can be a great litmus test for your FTP accuracy.

If you can sustain 40 minutes at FTP with minimal rest and don’t feel thoroughly challenged, at least eager for recovery during the final minute or two of each effort, then chances are your FTP is too low. The same fix of raising your FTP 2-3% is suggested.

How to Make Sure Your FTP Is Accurate

There’s only one sure-fire way to make sure your FTP is accurate, and that is through regular testing. With time, FTP testing will transform from something exciting to something dreadful and then back to something exciting again. If you have any doubts in the accuracy of your FTP, you can apply that quick fix of a 2-3% intensity increase until you feel you’re in the right spot, but I always advocate testing as the best way to resolve this issue.


Listen to Certified Cycling Coaches Discuss FTP Testing

Low FTP is one topic we covered in episode 26 of the Ask a Cycling Coach podcast. Listen to the episode’s full recording below to hear this and other questions from cyclists get answered by our certified cycling coaches.



Additional Notes

TrainerRoad’s Ask a Cycling Coach podcast is dedicated to making you a faster cyclist. It gives you the chance to get answers to your cycling and triathlon training questions from USAC certified coaches Chad Timmerman, Jonathan Lee and special guests. Learn more about other topics we covered in the latest episode with our resources below:

  • Do different types of trainers affect your FTP?
  • How inertia affects FTP
  • How to use cycling to lose weight
  • How power relates to VO2max
  • What should females know about body fat analysis
  • Is it normal to not see an increase in FTP?
  • Does expensive cycling kit make you faster?
  • Is your FTP too low?
  • What is VO2max?
  • Does VO2max training make you faster?
  • What your body goes through during an interval workout

If you have a question that you’d like to ask Coach Chad, submit your question here. We’ll do our best to answer them on the next episode of the Ask a Cycling Coach podcast.



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Jonathan Lee

Jonathan Lee is a Level II USA certified cycling coach and the host of the Ask a Cycling Coach podcast. His background in the sport of motocross has translated into a passion for cycling, mountain biking and all things training. If you have a training question, submit your question for Jonathan to answer on the next episode of TrainerRoad’s podcast.

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