How do you analyse power meter data?

Once the preserve of the professional elite, the power meter is now used by a large number of amateur cyclists. It has become an essential tool that enables quality training and precise performance tracking.

Your power meter collects usable data during and after your ride. This information is invaluable for assessing your effort, identifying your areas of improvement and building your training plan. Probikeshop explains how to analyse the data from your power meter.

A few reminders about power meters

A power meter is a valuable tool for cyclists looking to improve. Specialist brands are offering increasingly affordable models.

Choosing your power meter

There are several types of power meter:

Power meter crankset;

Power meter crank arm;

Power meter pedals;

Power meter hub.

Cost and measurement accuracy are the main selection criteria to consider. Pedal and crankset sensors have the advantage of providing separate measurements for the right and left leg. With this data, you can detect and correct any imbalance in your pedalling cycle.

The benefits of the power meter

Your power meter allows you to know instantly the power you are producing during your effort. The power data is expressed in watts (W) and calculated with every pedal stroke.

Power is a raw piece of data that expresses the cyclist's performance level without any interference. It is preferred over heart rate as a reference metric for measuring training load and effort intensity. The combined analysis of power and heart rate is very valuable for gauging form and fatigue.

During and after a cycling ride, your power meter is used to:

Establish your reference power profile;

Define your intensity zones and calibrate your training exercises accordingly;

Maintain a consistent effort relative to your potential;

Plan your training;

Track your fitness/fatigue level and your progress.

How do you train with a power meter?

Your power meter is properly calibrated — you can start training and discover all the benefits of this new tool.

Determining your rider profile

The first step is to run some tests to assess your physical potential. Your power meter allows you to establish your "rider profile" (peak power record or PPR). The aim is to collect reference power outputs over efforts of 5, 10 and 30 seconds, and over 1, 5, 20 and 60 minutes… By linking a wattage value to an effort duration, this PPR highlights your strengths and weaknesses. It also helps you track your progress throughout the season.

After a proper warm-up, here are the tests you can carry out with your power meter:

10-second sprints to find out your maximum power;

30-second sprints to assess your lactate tolerance;

A maximal 5-minute effort to determine your Maximal Aerobic Power (MAP);

A 20-minute all-out effort to estimate your anaerobic threshold;

A ride lasting more than 2 hours to assess your endurance qualities.

From the data collected, complete your power profile. Don't forget to weigh yourself before carrying out these tests, so you can relate the recorded power data to your weight (expressed as W/kg). This power-to-weight ratio is key to understanding your potential in the mountains. For example: a 62 kg cyclist who produces 320 W at threshold (5.1 W/kg) will be a better climber than a 78 kg cyclist who produces the same power (4.1 W/kg).

Targeting your training intensities

From the initial data provided by the power meter, notably the MAP, you can identify your intensity zones. These correspond to the different effort levels you can sustain during training. The ESIE scale ("Subjective Estimation of Effort Intensity") by Frédéric Grappe classifies and describes 7 intensity zones, indicating a percentage of MAP and HR for each one. You simply need to calculate your target power for each intensity, based on your MAP, to make the following table your own.

The ESIE scale by Frédéric Grappe, based on HR and MAP:

Intensity zone (exercise duration)	Max HR	MAP	Perceived exertion
i1 - Light intensity / Recovery (several hours)	< 75 %	40 - 50% MAP	No muscle pain Very easy conversation Exhaustion after several hours
i2 - Moderate intensity / Base endurance (several hours)	75 - 85 %	50 - 60% MAP	No muscle pain Easy conversation Exhaustion after 3 - 4 hours
i3 - Sustained intensity / Tempo (1-2 hours)	85 - 92 %	60 - 70% MAP	Muscle pain increases + Laboured conversation Exhaustion after 2 hours
i4 - Anaerobic threshold intensity (20-60 minutes)	92 - 96 %	75 - 80% MAP	Muscle pain increases ++ Difficult conversation Significant exhaustion after 20'
i5 - Supra-maximal intensity / MAP (5-10 minutes)	96 - 100 %	100% MAP	Muscle pain increases +++ Very difficult conversation Complete exhaustion between 5 and 10'
i6 - Sub-maximal intensity / Lactic anaerobic power (30-120 seconds)	100 %	1.5 x MAP	Significant nervous fatigue Maximum muscle pain Impossible to hold a conversation
i7 - Maximal intensity / Alactic anaerobic power (< 7 seconds)	90 - 95 %	2.5 x MAP	Very significant nervous fatigue No muscle pain Feeling of exercising while holding your breath

The power meter helps you precisely target the right zones during training. This precision in measuring effort makes it possible to plan quality sessions. The training plan becomes more effective because it can schedule the necessary workloads at the right time and for the right duration.

Some tips for making the most of your power meter

Once your power profile has been established and your intensity zones have been calibrated, you will carry out your training exercises. For example: if you need to perform a threshold effort (intensity 4) with a 4 x 5' repetition, you will try to stay as stable as possible around your threshold power.

Set your cycle computer to display your average power over 3 or 5 seconds. This will help you avoid fluctuations and give you a more stable value to hold your target power.

Watch your cycle computer closely during your intensity efforts. Outside of your exercises, a quick glance from time to time is enough to check your pace.

It is always easier to produce watts when climbing. The ideal is to find a gentle, steady and sufficiently long gradient to be able to carry out your training exercises.

Do not focus solely on power — keep an eye on your heart rate too. Since your HR can vary depending on altitude or fatigue, it is useful for managing your effort.

In competition, the power meter helps you manage your effort all the way to the finish line. Once again, simply glance at the screen from time to time to reassure yourself about how you are feeling.

The relevance of reading a power meter varies depending on the type of effort. It is most important during fairly long efforts where pacing is paramount – such as a time trial or a sustained climb.

Analysing power meter data

The usefulness of your power meter is not limited to the duration of your ride or race. By uploading your activity for the day, you can analyse the recorded data in depth.

Analysing data on a cycling training app

There are several training apps, such as Strava or Garmin Connect, which offer simplified analysis of your rides. These tools provide more or less advanced features (some modules require a paid subscription). Sites such as Training Peaks or Nolio provide particularly detailed data to optimise your training.

First of all, you will find all the figures you need to establish your power profile (max power, MAP, threshold…). They help you identify your strengths and define the races that suit you. For example: a rider who excels over 30" has punching qualities, while a cyclist who performs well over 20' is strong in time trials. This PPR helps you choose your areas of improvement and direct your training accordingly. If you want to perform at a high level, it is more worthwhile to specialise in your preferred discipline.

Note that using the power meter in a race is an excellent way to update your PPR, as record power outputs are often produced in competition.

Useful data for planning training

After each session, the data from your power meter allows you to analyse your effort for the day. You can check whether you have correctly respected the planned intensity zones. You can continue the analysis by cross-referencing the power curve with your heart rate and cadence.

Over the longer term, all the recorded data is useful for measuring your workload and planning your training. The power produced during a session can be used to calculate a Training Stress Score (TSS). This TSS is measured from your intensities: the harder you ride on a given outing, the higher the TSS value. This allows you to manage your workload more precisely and better control your fatigue. The idea is to plan a progressive build-up in order to arrive in peak form at the right moment.