When we talk about racing with a power meter, we instantly have the picture of Chris Froome staring at his stem in our minds. This is partly the reason for this particular article. Yes, we may be able to pace ourselves during a cycling race with a power meter, but we still have to ride over the obstacles the course presents. Therefore it becomes more complex.
In MTB races in particular, the power data becomes extremely stochastic (highly variable) in nature due to the nature of the terrain. So if it is difficult to pace yourself using power on a MTB, what are some of the other benefits?
Recording the demands of racing with a power meter is a perfect means of tailoring your training to increase the specificity of your training sessions (i.e. make your training more similar to the demands of racing). Analysing race power data will identify specific periods in the race of particular demand. Designing a training session, which mimics these demands repeatedly, is an excellent manner in which to improve your race performance. Note, however, that these very specific sessions should not replace all phases of your training. They should be included toward the end of a periodised training plan to add that cherry on top of the training adaptations you have already made.
Further, race data is also an excellent way in which to track and ensure progression. Post race analysis should consist of keeping track of your best 5 seconds, 30 seconds, 1 minute, 5 minutes, 10 minutes, 30 minutes and 60 minutes average power produced during the race. Although these numbers may also be dependant on race terrain, trends over time should be used to establish if there is progression and importantly, to identify potential weakness. Furthermore, an important variable when analysing power data is normalised power, or NP. Normalised power, as well as other important key terms are defined below. Normalised power should also be plotted and compared to similar races of equivalent durations.
Understanding Power metrics:
Normalised power (NP): Normalised power is calculated from an algorithm to account for the random nature of power data and should be representative of the power you could have sustained for the duration of the ride. NP is more representative of the physiological demands of racing when compared to average power.
Functional threshold power (FTP): Is the maximum constant power you can sustain for 1 hour.
Intensity factor (IF): Your IF is calculated from the fraction of your NP/FTP. You should therefore not be able to sustain an IF of >1.0 for more than 1 hour.
Training stress score (TSS): TSS gives an indication of how hard a training ride or race was. An all out 60 minute time trial should result in a TSS of approximately 100. A mountain bike race may be anything from 100 TSS (short cross country race) to 400 TSS (a tough day at the Cape Epic).
Although I mentioned that it is very difficult to pace yourself during an MTB race, you may use your IF (intensity factor) to ensure that you are not pushing yourself beyond what you are able to sustain for the desired duration. If your race is only 1 hour long, it may be realistic to maintain an IF of 1. However, if you are doing a race with an expected finishing time of 4 hours, do not try and maintain an IF of 1 for the first hour. You should base your targeted IF off previous races of similar intensity. Only experience with racing with power will assist you in pacing yourself using your IF.
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