Whether you’re starting a training program or checking in on your progress, one of the best ways to get an idea of your fitness is with an FTP test.
What is FTP?
FTP—functional threshold power—is the metric most indoor training programs use to build your training plans. The number, given to you in watts (e.g. 200w) is a personal threshold. Theoretically you should be able to sustain long rides at power targets below your FTP, while time spent training above your FTP will cause you to fatigue more quickly.
Some will say that FTP is the power you could theoretically hold for an hour, but it’s a bit more complicated than that. Andrew Coggan, author of Training and Racing with a Power Meter, defines FTP as: “The highest power a rider can maintain in a quasi-steady state without fatiguing.” Your FTP is considered your “threshold” or “lactic threshold” power—you’re riding at the upper limit of your blood lactate or your maximal lactate steady state. For most cyclists that means your FTP is actually a power level that you can sustain for somewhere between 30 to 70 minutes.
What FTP test should you do?
Before you get started with your FTP test be sure you’ve prepared properly.
Programs like TrainerRoad and Zwift offer a few options for FTP testing. Here is a breakdown of the main three.
Best for: Fist FTP test, beginner-novice riders, cyclists new to trainers
The ramp test is recommended by both Zwift and TrainerRoad as the best method of FTP testing for any cyclist. If you’re just getting started with indoor training, if you’re not familiar with 20-minute efforts, or (and this is a big one) if you just want to minimize the mental fatigue of testing then the ramp test is for you.
A ramp test is exactly what it looks like: Every minute the power target increases and you keep going until you are no longer able to hold the assigned power number. This testing method is great for anyone who has no idea what their FTP is. Although the last portion of the test is pretty brutal, all things considered you don’t spend much time in the why-am-I-doing-this zone.
Best for: Experienced cyclists, those looking for more accuracy
The 20-minute test is much more mentally taxing than the ramp test, but the result more closely simulates the long, steady, aerobic efforts of most cyclists. This test is good for cyclists who have done 20-minute efforts before and have an approximate idea how to pace themselves. It helps to have a realistic power target in mind when doing the 20-minute FTP test, otherwise you might find yourself going too hard or too easy off the start.
Note: Zwift has two 20-minute tests, FTP Test and FTP Test (shorter), the only difference is a shorter warmup and cooldown.
Best for: Cyclists that spend time performing in VO2 max
According to TrainerRoad, the 8-minute test is, “best for shorter-duration athletes who are familiar with performing at VO2 Max, like criterium racers, cyclocross racers, and XC mountain bikers.”
For most cyclists the 8-minute test isn’t the best way to find your FTP. It does offer a nice middle ground between the mental taxation of the 20-minute test and the anaerobic efforts of the ramp test, but for more accuracy the 20 minute test is best (and since you’re doing two eight minute efforts it’s still pretty mentally taxing).