Training with Power

Anyone who’s had the dubious pleasure of riding with me will know about my tireless, and doubtless, tiresome, enthusiasm for training with power.  I started gently this year hiring a Powertap from the estimable guys at CyclePowerMeters (really nice people, occasionally sketchy service!) before committing to a reasonably serious financial investment.   At the end of the day cash is in finite supply and a power meter has to justify itself against any other number of competing potential purchases.

Since then I’ve decided to go full on, with a power meter accompany my every pedal stroke.  I have a CycleOps 300PT indoors and have bought the Powertap and got Geoffrey Burglars to build me up a set of wheels.



So why?  Well.  Accuracy and feedback.  As soon as you want to do more than just ride your bike and do some actual training, you’ll want to be able to measure the work that you are doing.  There are plenty of surrogates that have been used with great success for many years.  Bike computers and heart rate monitors have been around for ages and provide useful feedback, but both have serious flaws.  Speed is clearly affected by almost everything – wind, grade, traffic, you name it.  Heart rate is much better and until the advent of affordable power meters was the only way the amateur rider was able to gauge their efforts.  However, heart rate, whilst providing a window into what is happening inside your body, is also compromised by confounding variables and other factors which make it imperfect for gauging the effort you are making.  The heart rate response seriously lags behind effort, drifts over time and is affected by temperature, stimulants and fatigue.


Power on the other hand is a shining beacon of accuracy and consistency.  Power meters don’t care if you’re knackered, high on caffeine or riding into a beastly headwind – a power meter will provide an instant and accurate guide to the work you are doing.


So what?

Good question.  Neo-luddites will tell you that Eddy Merckx didn’t need a power meter.  And they are right.  But would he have used one if they had been available?  You betcha!


Well, for a start accuracy is important in it’s own right – being able to precisely and consistently target intervals for example has considerable merit.  However, there is a more important factor for me that considerably increases my motivation.


Someone rather cleverer than me explained this using an analogy which I’ll crudely paraphrase.  Imagine going to a gym that had no indication of the weight you were lifting.  In fact, imagine that the weights were concealed.  It’s easy to see how much more motivating it is to work out knowing how much weight you are pushing and how much easier it is to gauge one’s progress.  Or, for F1 fans – how much less exciting is qualifying now the result is a combination of performance and an unknown fuel load?


This, of course, is partly a reflection of ones personality.  I’m sure there are riders, far better men and women than I, that can do a seriously hard interval session and be happy with their perception of the quality of the  effort.  However, it is much much easier for me to motivate myself knowing that as soon as I’ve finished I can download the data into a software package that will tell me quite precisely what I’ve achieved.


What can you do with a power meter then?

My use may well not be typical but I use it to do the following

  • help me guide my intervals on the indoor trainer
  • provide useful stats on my indoor and outdoor training
  • allow me to accurately track my progress and build a training plan


I do a fair bit of indoor training and this mostly takes the form of 2×20 and 3x20s.  By using a power meter I can control and target consistent efforts and get great stats at the end of the ride.  If having a power meter has a strength it is here.  Intervals really expose the shortcomings of heart rate measurement – the lag and drift of the heart rate response make it not quite useless, but not far off.  It’s not uncommon for my heart rate to steadily increase throughout the entire 20 minutes of an interval.  If I was doing shorter interval this failing would be even more apparent.


In addition to the instantaneous feedback of effort there are some very cool things you can do with power data.  These ideas seems to have been mostly inspired by Andrew Coggan and have been documented in his excellent book Training and Racing with a Power Meter.  He has also been heavily involved in the creation of the ‘gold standard’ power analysis software TrainingPeaks WKO+.  There are measures of the average effort that reflect the physiological cost of each ride (Normalized Power), how this compares to ones threshold power (Intensity Factor) and an overall score for each ride (Training Stress Score).


Beyond the analysis of individual rides, there are cumulative measures of the short-term impact of recent rides (Acute Training Load) and the longer-term accumulation of fitness (Chronic Training Load) that can help you understand fatigue and also allow you to plan a steady increase in training load.


I plan to do a much more technical post to explain these concepts soon.


Lastly you can perform your own testing.  Functional threshold power (FTP) is widely considered to reasonably correlate with cycling prowess and can be reliably measured with a Powertap.


Anyway,  enough rattling on.  I’m in little doubt that, for me at least, a power meter is an invaluable tool for monitoring rides in both the short and long term and for providing me precise information that I can use as a source of motivation.

No Comments on “Training with Power”

  1. 1 Simon Roberts said at 11:37 am on October 31st, 2009:

    I use a powermeter for indoor work, and find it invaluable. I struggle a bit more with using it on the road and particularly in events, I find it a bit distracting. It reminds me of the Cavendish story: in one of his first hilly races, he rode up to Millar and exclaimed that he could not believe the peloton was riding at 500w up a climb. Next time Millar saw him, he had been back to the team car for some duck tape to conceal his power readings.

  2. 2 admin said at 10:08 pm on November 1st, 2009:


    Agreed about on the road use. The instantaneous power reading is not that interesting in its own right.

    However, analysing the data after the ride is interesting – especially if you’re into Normalized Power, TSS, CTL, ATL and TSB.

    Nice anecdote by the way. Have you read Cav’s book? It’s a surprisingly good read.



  3. 3 Scott Phillips said at 9:13 am on November 17th, 2009:

    G’day Paul from New Zealand.

    Just came across your blog and loving it. I’ve just caught the road cycling bug and have found your blog really helpful. Keep up the good work!