What is normalised power and what can it tell us cyclingtips grade 9 electricity unit test


What is the best way to measure how hard a ride is? Should you simply look at distance and time? Or do you delve deeper and analyse your average power? For those of us lucky enough to have a power meter, average power can paint part of the picture but in order to fully understand just how hard a ride is, normalised power is a much more useful tool.

Normalised power is an important metric for cyclists who train with power and it is valuable to understand how it works and when to use it. In order to build fitness, athletes put their body under stress during training. The body adapts to this stress through recovery and, in the next round of training, is then able to accommodate more stress, leading to increased athletic abilities.

Defining how “stressful” a block of training is can be a difficult task and you must consider every component, including the duration, frequency, intensity and “how hard” the rides were. While most of those aspects have straightforward answers, the “how hard” element is a difficult factor to quantify.

You can look at average power, but that is purely the average of your power throughout the whole ride. This is a simple measure to understand and at first can seem like a worthy way to measure the effort of a particular ride. However, it can be limited in its function.

On the other hand, if you rode an undulating course and did an hour-long effort, trying to average 200 watts could be a much harder task. You would need to hold more than 200 watts uphill as the descents would neutralise those efforts and bring your average back down.

This is where normalised power comes into play. Normalised power will take into account the variance between a steady workout and a fluctuating workout in order to quantify the physiological cost. This means that for a highly variable workout, normalised power will be much higher than average power. For a steady, consistent workout, the two values will be very similar. Normalised power in action

Through these figures, you can already see how Urán’s effort was extremely measured and steady. The two numbers are very similar, with the difference likely to be due to a short, two-kilometre downhill section where Urán wouldn’t have been pushing the pedals as hard. Normalised power accounts for that and adjusts accordingly.

The 181km stage featured three hors categorie climbs, which meant three long descents. Look at Urán’s average power for the ride and you might be tricked into thinking it was a relatively easy stage. Once you realise his normalised power was almost 80 watts higher (a difference of 33%) you can start to understand the value of the metric.

Normalised power provides a more realistic way of representing a rider’s workload than average power. It can be imagined as the power a rider could have maintained for the same physiological cost had their power been perfectly constant. The examples above show how it is particularly useful when considering hilly races where a rider’s power varies a lot.

The challenge for any athlete is to know how much stress they can put their body under and how much recovery will be required to maximise adaptation and, in turn, fitness. Measures such as normalised power allow athletes to better understand how hard a particular ride was.