POWER ZONES

Power meters are a relatively new technology used in cycling. Surprisingly, they have been commercially available since 1989 (only six years later than heart rate monitors), however the popularity of using power meters has only really risen in recent years. As with heart rate zones, I recommend you calculate your power zones using your threshold power. Doctor Andy Coggan is an internationally recognised exercise physiologist. In his book ‘Training and racing with power’, he states: “Power at lactate threshold is the most important physiological determinant of endurance cycling performance because it integrates VO2max, the percentage of VO2max that can be sustained for a given duration, and cycling efficiency. As such, it is more logical to define training zones/levels relative to an athlete’s threshold power than it is to, for example, define them vis-avis power at VO2max.” Some of the more common methods of power zone calculation include: Andy Coggan Method CTS Method Joe Freil Method I-Levels Those of you using TrainingPeaks software may have noticed that you now have the option of using iLevels as your method for setting up training zones. This method was developed by Dr Andrew Coggan and it uses functional threshold power (FTP) as well as taking into account the unique physiology of each athlete by using the power-duration curve. For example, two riders may have the same FTP but have very different power duration curves – one having more of a ‘sprinter’ phenotype and the other having more of a time-triallist phenotype. Using the previous (Classic) Coggan method, both of these athletes would have exactly the same training zones. However, using the new iLevels, the training zones would be quite different in terms of both power and time spent at such power. The other big advantage to using the iLevels, is that it takes into account your current level of fitness. Any changes to your power-duration curve or FTP will automatically result in changes to your iLevels. The chart below shows a comparison in the Classic Coggan Levels and more complex iLevels: