Bytagand the publication "Normalized power in cycling"
When using a power sensor, on route or on home trainer, the normalized power (or weighted power, Normalized Power in English or even NP) displayed on your meter or in your activity report is more important data than the average power. We explain why.
By Guillaume Peephole – Photos: ©Sram/©Shimano
For cyclists and triathletes, normalized power is one of the most critical, yet useful, pieces of data to understand.. This is'an adjusted measure of the average power of an activity, which more accurately reflects the intensity level of the activity.
=> SEE AS WELL : Power in cycling
Measuring power in cycling, whether using a power sensor in the crankset, pedals, hub or transmission mechanism of the home trainer, has become popular in recent years and has allowed many practitioners to progress by optimizing the time spent training. Indeed, measuring power instantly reflects the intensity level of an exercise, unlike measuring heart rate, which always reacts with a latency time.
=> SEE AS WELL : Power Meter User Guide
But power data is sometimes difficult to interpret. Not all efforts are equal in terms of energy costs and small variations or increases in intensity can completely change your perception of effort as well as your ability to achieve your goal. This is why the notion of average power imprecisely reflects the notion of difficulty of an effort, and that normalized power is more appropriate for comparing outputs with each other.
=> SEE AS WELL : Working on endurance, with a power sensor or a heart rate monitor?
Why is average power not always relevant data?
Anyone who has even a modicum of experience using a power meter knows that it is difficult to maintain consistent power when the intensity is high.. And it is precisely in these conditions that the average power proves interesting to note, on a climb of a pass, a time trial, or a test 5 or 20 minutes for example, because It defines your level of physical fitness and serves as a reference to determine the training intensities that will help you progress..
=> SEE AS WELL : The different training intensities
However, average power loses all meaning under other conditions, as over the total length of a training session taking into account the warm-up, cool-down or traffic conditions, during a race or during an outing with other cyclists. In a race for example, there are many moments where you stop pedaling caught in the slipstream of the peloton, but where you have to push very hard when restarting at the end of a bend or to follow or provoke the various attacks. It is these repeated accelerations which are very costly in terms of energy and which disrupt the management of your effort. The average power of a race can be surprisingly low compared to the actual difficulty. Whereas conversely, a session at stable and regular intensity over a route flat without circulation or on a home trainer can show an equivalent or higher average power without the effort being comparable.
Wanting to follow the average power of an outing can also lead to the same excesses as being interested only in the average speed of an outing.. In seeking to optimize the time spent training by taking into account only this value, you might be tempted to look for the most favorable terrains to maintain a sustained average power, or to neglect the recovery periods necessary for good progress. In other words, referring to average power is most often counterproductive. Hence this notion of standardized power, more reliable for assessing the level of intensity of training or competitions.
=> SEE AS WELL : How to improve average speed?
Reference value
Developed by Dr. Andrew Coggan (the inventor of the famous test FTP) in the mid-2000s, normalized power reflects the disproportionate metabolic cost of high intensities, weighting intense efforts and minimizing periods of low-intensity pedaling. To put it simply, while average power is simply a reflection of the power you actually produced during a ride, including periods of coasting, normalized power is closer to what you could have done with the same level of effort, if you had been riding at a perfectly steady pace.
The calculation of normalized power results from a complex algorithm, fortunately integrated today into all meters that support power sensors, as well as GPS race or training data analysis platforms such as Strava, Garmin, Wahoo, Hammerhead, etc. On your meter, you can choose to display the average power (not very relevant over the duration of a ride) and/or the normalized power.
Normalized power is also widely integrated with other measures in most software that helps assess training difficulty or load, such as intensity factor (Intensity Factor), or the stress level of training (Training Stress Score). But You can also use this concept to directly analyze your performance and guide your efforts. The standardized power can be used as a reference on a cyclosportive to help you determine if you are adopting a good pace in relation to your abilities, for example by avoiding starting too hardBy checking your normalized power 20 or 30 minutes after the start of the event, you can assess whether you are at risk of over-revving or whether you have every chance of finishing in the best possible conditions.
Personally, I display three power data on my meter when I use a power sensor: the smoothed power over 3 seconds (easier to follow than the instantaneous power), the normalized power of the entire output, and the average power between two intermediate times, which allows me to use this value only during a very specific exercise, that is to say when it is relevant as explained above. Because it is the display of the standardized power that allows me to compare the intensity of one output to another.
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Bytagand the publication "Normalized power in cycling"
