Power

What is it?

Power is the amount of energy a cyclist or runner is generating, measured in watts.

Your power as a percentage of functional threshold power (FTP), or the number of watts you can hold for one hour, is a key indicator of effort level and helps determine the zone or zones you worked out in. (You can change or enter your FTP in profile settings.) A power meter or smart trainer is required to track this for cycling. For running, it’s estimated based on your weight and pace.

How do I use this?

Overall, your power gives you a good read on how strong you were – the higher the number, and the easier it felt, the better.

You can also see the impact this activity had on your training with Power Zones: Z1-2 is easy and ideal for recovery, Z2-3 is good for moderate endurance, and Z4 and up is considered intense. For cyclists, your Power Curve shows the maximum power you held for various time intervals during your ride (e.g. 5 seconds, 5 minutes), and you can compare it to previous Power Curves to see if you’re improving.

Read the extended help article below for more details, including determining your FTP.

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Strava subscribers who ride with power meters can start training more intelligently with advanced power training analysis.

Available Features:

• Weighted Average Power looks at all of your power variations and provides an average power for your ride. This is a better indicator of your overall effort than simply taking your average power.
• Training Load is calculated by comparing your power during a ride with your Functional Threshold Power (FTP) and seeing how much load you put on your body during the workout. Training Load is a great way to determine how much rest you need after your workouts.
• Intensity is Strava’s way of showing how difficult a ride was.  Strava looks at your Weighted Average Power for the ride and compares it to your FTP. For example, if your Weighted Average Power is 225W and your FTP is 300W, then your Intensity would be at 75%.
• Power Curve shows your best average power for time periods of one second up to the length of your ride. We pinpoint your best efforts during a ride and you can compare them with your best efforts in the last six weeks, the current year, and years past. The Power Curve can be displayed in Watts (W) or Watts per Kilogram (W/kg.) Other athletes may be able to deduce weight using information displayed in the power curve. To control which stats are visible on your activities, see our article here.

• Power Distribution by Power Zones: While the Power Curve shows your best efforts for given periods of time, Power Zone charts take each second of power from your ride and distribute it by training zone based on your FTP.

 

• Power Distribution by 25W Increments: Similar to the Power Distribution by Power Zones, the Power Distribution by 25W Increments simply puts each one second of power into a 25W training zone from 0 to the highest power output on the ride.

• Power Curve in Training Section: Similar to the Power Curves on your activities, the Power Curve in the Training section allows you to compare any two of your power curves. For example, you can compare the last six weeks to all of the previous years and see how you’re progressing.

Calculating Your FTP

We recommend you test for your FTP at least every few weeks to a month while you're training. Here are some tips to get the most out of your FTP testing:

• It's extremely taxing on your body (and your training program) to continuously push out 60-minute max efforts. It's also difficult to find a stretch of road where you can ride for 60 minutes uninterrupted and maintain a steady wattage. Thus, the easiest way to calculate your FTP is to test your best average power for 20 minutes and then subtract 5%. We believe 20 minutes is enough time to stress the same physiological systems as a 60-minute effort would and it is easier to consistently do within your season.
• Try to reproduce the same conditions for each test, for example, the same stretch of road or the same trainer/rollers.
• Make sure you are fresh (the previous few days should be light in terms of training load).
• Properly warm-up.

FTP Management in Settings

• On the web, go to your Settings page by hovering over your profile picture in the top right and selecting Settings.
  • Click on the My Performance tab on the left side of the page.
    • Click to edit under Functional Threshold Power towards the bottom of the page.
    • You can also add date ranges for your FTP in your My Performance settings on the web. Old rides will retain the zones and stats for your fitness at the time instead of updating to match your current output. You’ll also see your past numbers reflected in your Fitness graph.
• On the mobile app, select You > Profile and select the option to Edit Profile.
  • Enter your Functional Threshold Power in the appropriate field under Performance Potential.