In cycling, the power meter has become a ubiquitous training and racing tool. Collecting data from your rides and races is useful and can be used as a measure of performance and fitness. Training with a power meter to specific intensities can also help an athlete dial in their training to ensure maximum benefit for their efforts. In order to set training intensities, it is necessary to test your current level of fitness. Since it is early season right now, this is a great time to establish your baseline fitness with a power meter test.
There are a couple of ways to conduct a power meter based test. One is in an exercise physiology laboratory, where you will also be able to collect VO2 max and blood lactate data. The other type of testing is outside or on your trainer – a field test. This is the most accessible type of testing for most athletes. I recommend either two by eight minute tests or a single 20 minute effort. These efforts are all out, steady efforts. Ideally, testing will be done on a slight uphill, where it is easier to maintain consistent pedaling resistance.
The two eight minute tests are mentally easy to perform and give insight into an athlete’s ability to recover between hard efforts. After a good warm up (just as you would for a race) begin the first interval. Seated riding is recommended for even effort. Allow a full 10 minute rest between efforts. The highest average power from an 8 minute segment is statistically about 10% higher than an athlete’s true threshold wattage. The 20 minute power test is also more manageable than a full 60 minute time trial (used to establish lactate threshold in the lab). The average power from a 20 min effort is about 5% greater than threshold wattage.
Once you have obtained an average power (say 300) from either test, calculate your estimated threshold wattage (270 if this was from the 8 minute test). From this Functional (estimated) Threshold Power (or FTP) you can calculate training levels. Endurance training will be about 56-75 % of that FTP, or 151-202W. Tempo effort, which I recommend a lot for aerobic base training and building glycogen stores is 76-90% FTP or in our example 203-243W. Training at threshold will end up around 243-285W in our example, and VO2 max efforts are done @ 286-324W. Play around within these recommended ranges to figure out what works best for you in terms of fatigue and fitness gains. Physiology is not crisply defined within every person, rather multiple energy systems are functioning simultaneously, and transition into the next system as you increase in effort.