What is FTP?
Functional Threshold Power, or FTP, is the average power you can sustain for approximately an hour of maximum effort cycling. It's a good metric to measure your cycling fitness and to assess your progress over time. Ie as you get fitter, your FTP will rise. Importantly, FTP is also an effective way to set yourself power training zones.
How to Find Your FTP
There are a few different ways that you can find your FTP. The most common way is to do a timed test where you ride for 20-30 minutes at a maximum intensity and then take your average power output for that effort. Once you have your average power, you can minus 5% and you’ll arrive at your FTP.
One important note is: do not ride the first 5 minutes of the test too hard. While the test is a maximum effort, it’s important to progressively increase the power throughout the test so you can absolutely empty yourself in the last five minutes. Go too hard too soon and you will tire before the end of the effort. If this happens, the results will be less accurate.
You must also be well fuelled for these tests, it’s important your glycogen stores are not low as these hard efforts really depend of glycogen as an energy source. Having a substantial meal 2-3 hours before and an energy gel about 20mins before is a good plan.
Remember, cycling FTP tests are extremely hard! They should only be done when you're well rested and have time to recover for a few hours afterwards.
Here is a step by step guide on how to measure your cycling FTP outdoors:
Find a flat, traffic-free stretch of road that's at least 12 miles long.
Warm up for 20 minutes, spinning easily in a gear that's comfortable.
When you're feeling good, ramp up the intensity and settle into a hard effort for 2 minutes to really open the legs and lungs up.
Ride easy for 5 minutes to recover.
Ride all-out for 20 minutes remembering not to go too hard too soon!
Once you've completed the final effort, cool down by spinning easily for 10 minutes.
Take your 20 minute average power and minus 5 % to find you FTP.
To be sure that your FTP is accurate, it's best to test every four to six weeks and make adjustments to your training plan accordingly.