There is so much confusion out there about Functional Threshold Power. Ask a group of riders what they think Functional Threshold Power is and you will probably get the answer that it is the maximum power that they can hold on a steady state effort for an hour.

So this begs the question, if that's what you think, why are you not doing a 60 minute test? Because A, it is a hard test that requires a lot of pacing skill, and B, it won't give you a number that you can brag about in the bike shop!

What is FTP?

The most useful way to  define FTP is that it is the maximum average power that a rider can output in a steady state effort, for a reasonable amount of time, until fatiguing. In my experience, for many riders this is around the 35 minute mark.

So how do people work out FTP?

There are 2 popular methods:

  1. Use 95% of 20 min critical power

  2. Use 90% of VO2Max power

Both of these methods have significant limitations. For example, for the 20 minute test to be anywhere near 'correct' you need to precede it with a hard 5 minute effort to remove some of the freshness from your legs. I see plenty of riders just warm up and then smash out a 20 minute effort. This will give you a very high reading, more an FTPego than an FTP. The VO2Max test is using yet more interpolation and is a very hard test to do for less experienced riders.

So which test should I do?

For me it all comes down to what discipline you ride and what type of rider you are physiologically.

For experienced riders, who compete in short duration events, then the VO2Max test will probably provide the most useful FTP and hence training zones. 90% of the best of 2x8 minute efforts works well.

If you are riding longer duration events then the 20 minute test is better as long as you do the hard effort beforehand. For many riders using 95% of their 20 minute test will still give too high a FTP if their aim is to improve the duration that they can output decent power for.

For experienced riders who are more diesel engines (the majority of older gran fondo riders), being able to crank out a pretty decent power for a long time, but have limited high end capacity, then I use the 60 minute test on the road. This will give training zones that are realistic to the event efforts (specificity) and achievable, especially at the higher end. For most athletes using the 20 minute test in isolation will result in an FTPego that is way too high. This will mean that aerobic work will be done at too high an intensity and the high intensity work will be too hard, harming interval repeatability.

In short, each rider needs an FTP that is 'right' for them as a rider. FTPegos are great for bike shop bragging but will actually lead to poor training and hence results. With so many software applications out there now, each trying to grab a share of the massive training market, it has become a minefield of confusion.

For those of you who use a coach, getting this stuff right for you as an individual rider is what you are paying for. Your coach will be able to:

  • Design a training plan that addresses your key strengths and weaknesses. (and work out the best way to calculate your FTP!!)
  • React to changes in fitness and modify training.
  • Help you through periods of poor health.
  • Avoid injury and overtraining.
  • Adapt your training to fit around work and family life.
  • Provide emotional support when things get tough.
  • Choose races and events that suit you as a rider.
  • Provide objective analysis of results.

In my experience self coached riders tend to:

  • Just focus on the elements of their cycling that they are already good at.
  • Don't react to changes and just keep doing the same thing time and time again.
  • Try and train through periods of illness.
  • Train too hard, too early and become injured.
  • Are not realistic with their time demands.
  • Tend not to talk to anyone when things don't work out as planned or get tough.
  • Choose unsuitable races and events given their physiology and strengths and weaknesses.
  • Rarely analyse results.

Yes we all want to get our FTP as high as possible but only in the wider context of our own physiology and target events.

We have a range of training programmes which are now available on Training Peaks and have a few of our Bronze and Silver Coaching places still available.

Please contact me to have a chat about your training and riding

Rob Wakefield is a fully qualified Level 3 Cycling Coach with the Association of British Cycling Coaches and founder of Propello, a cycling focused health and fitness business delivering Performance Training Programmes and Bespoke Coaching to cyclists anywhere in the world.

All cyclists who are looking to improve their speed, endurance or strength will benefit from a structured training programme. Propello Training will improve how your muscles, lungs and heart work and will enable your body to transport and utilise fuel effectively - making you faster and stronger for longer.

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