At CPL we’ve been using power meters since the turn of the century (it’s an interesting snippet of general knowledge that the SRM was invented as long ago as 1988). Riding with power has greatly enriched
our enjoyment and understanding of cycling for a long time but we realise that for many people power meters appear and indeed are a very new toy. With this in mind we’ve put together the following thoughts
on “getting started with power” in the form of a 10 point plan that picks up just as soon as you’ve finished
choosing a power meter
and remains relevant through the end of your first season with power.
- Collect some data
Once you’re chosen power meter is installed and ready to go our best advice is, for a while, to do nothing new. Just go out and ride, as you always did, but make sure your power meter is set up
properly and recording your power data. We’d suggest doing this for a couple of weeks, faithfully downloading your ride data at regular intervals, but not worrying too much about what it’s telling you.
The idea is to build up a profile of your typical power outputs and training loads for some initial analysis.
- Analyse your data
Depending on the device you’ve chosen your power meter may have come with some ride file analysis software from the manufacturer but, for in depth analysis, we’d recommend download the
free trial of WKO+ or Golden Cheetah. Load your 2 weeks of ride files and play around with some of the charting and analysis options. Understand your average power output and maximum average
power outputs across a range of durations such as 5 seconds, 1 minute, 5 minutes, 20 minutes and 1 hour.
- Field test your power to establish “FTP” & power training zones
Training by reference to heart rate relies on a set of “zones” defined by maximum heart rate but training with power relies on zones defined as some percentage of your “Functional Threshold Power” or FTP
which is the highest power you can expect to average for one hour. We say expect because you don’t need to ride an all-out 60 minute effort to estimate this number. In fact there are several recognised
ways to estimate this using field tests it but we’d recommend one of three:
- If you are a time triallist riding regular events of around 25 miles (40 km) then fine, use your average power from your next event.
- Most riders best 20 minute power tends to be around 105% of their best 60 minute power so you can use a 20 minute all-out test, divided by 1.05, to estimate FTP.
- Use something called the “Monod Critical Power” model to estimate FTP from 2 or 3 all-out tests of shorter durations (it works because of a relationship between a riders anaerobic work capacity
and sustainable power at increasing durations). We’d recommend tests of 1 minute, 5 minutes and 8 minutes if you don’t want to do a 20 minute effort. You can then use the
Monod Model on this site to estimate your “Critical Power” at all durations up to
60 minutes. Your 60 minute critical power forms your estimate of FTP.
Given your FTP in watts you can then calculate your power training zones; our Monod Model will do this for you.
Get used to training in terms of power zones. You’ll have noticed that the power number on your handlebars jumps around all over the place compared to heart rate but don’t worry, it’s all about averages
and continuous blocks of time spent in the right zone. Training in power zones works by targeting different energy systems and physiological adaptations (the names of the zones make these fairly obvious)
so get used to the terminology and how the different zones feel. The higher zones, the ones that bring on racing form, are best targeted via interval training. Have a look at our article
Interval training with power to get some ideas or consider consulting with a coach who embraces
training with power.
Schedule periodic fitness testing
The great thing about power, unlike heart rate, is that the raw data tells you if or how you’re improving. We’d recommend retesting your FTP every month or two to keep track of progress. If you have
specific racing goals then you may come up with more targeted tests such as sprint (5-10 second) power, minute power, or average power on a particular hill, the decision is yours. Keep in mind though
that most people and coaches will talk in terms of minute power, 5 minute power, 20 minute power and FTP. Do any testing when you’re fresh, perhaps first thing after an “easy” week scheduled at the end
of monthly training blocks. Depending on what these tests tell you, the level and timing of your goals you may take these tests results as a signal to amend your training.
Race with power
Power meters and power data are an excellent diagnostic tool to understand the challenges of racing and the reason why we very often cannot win. Always race with your power meter – any weight penalty is
insignificant relative to the value of the information – plus the race environment tends to test our abilities like no other. After the event study the demands of the race in terms of peak power at the
important durations mentioned above and understand where and why you hit your limits. The conclusions you draw here can be fed straight into the design of your future training plans.
Look for trends
Good physical form on the bike can be an elusive and mysterious thing that leaves even the professionals scratching their heads for more sometimes. Certainly you can better measure it with power data
but you should also study the patterns of what leads you to good form. There is always a trade-off between training you’ve done, absorbed and recovered from, translated into fitness, and training
you’ve done very recently but not yet recovered from, translated into fatigue. Knowing how to get the balance right in a way that’s specific to your body is an important skill. There is no “one size fits all”
solution to predicting form but the best analysis software such as WKO+ includes tools to help analyse form in terms of the “Performance Manager” chart.
Ask “What if?”
There is a very well understood link, rooted in the laws of physics, between a riders power output and speed on the road and it’s one of the things that makes power meters such an exciting tool. We use it
a lot on this site via the Power-Speed model. Having invested in a power meter you can use this relationship to think in some very aspirational terms that should serve as extra motivation to train in a
Optimise your aerodynamics
Power output you can now see, you should also know your racing weight from the scales. But the other big yet unseen factor which slows a rider down is aerodynamic drag. A few weeks or months into riding
and training with power you should be pretty much “thinking in power”. You will come to think in terms of how much power you need to ride at speed X and then how much of that power is due to weight and
how much is due to the aerodynamic drag of yourself, your bike and it’s components. Power meters enable the testing of aerodynamic drag via a couple of different
field test protocols which you can apply over and over to help minimise it. Nowadays components are increasingly designed and marketed in
terms of their drag properties and how much power they require to overcome that drag. If you’re looking to buy speed then don’t buy a frame or wheels marketed as “aerodynamic” until you
understand how to evaluate these, consider using our
aero components evaluator.
Review your season
With the end of your first season riding with power comes a very satisfying moment. For the first time you have loads of really insightful data through which you can look back and evaluate your season.
Where and why did it go well (or wrong), when did your form peak and what sort of training got you there? It is unlikely that, if you have really embraced power, you will ever doubt
the investment in a power meter or ever again choose to ride without one (excepting perhaps the day when the battery is flat or the device is with someone for a periodic
calibration). Your planning for the forthcoming season can now
take shape like never before and the path ahead of you will be very recognisable as you work to retrace and exceed the steps to fitness that you know you’ve taken before. Now do your club-mates a favour
and become a power evangelist!