What is Functional Threshold Power (FTP)?

Functional Threshold Power, or FTP, is a term that gets thrown around a lot in cycling circles. But what exactly does it mean, and why should you care? In simple terms, your FTP is the maximum power output, measured in watts, that you can sustain for roughly an hour. Think of it as the sweet spot where you can push hard without blowing up completely.

A Brief History

The concept of FTP was popularized by Hunter Allen and Andrew Coggan in their book "Training and Racing with a Power Meter." They recognized the need for a metric that could accurately gauge a cyclist's sustainable power output, allowing for more precise training and pacing. Before power meters became widespread, cyclists relied on heart rate and perceived exertion, which can be subjective and influenced by factors like fatigue and caffeine intake. FTP, on the other hand, provides a more objective and consistent measure of your fitness.

How is FTP Used?

FTP serves as the foundation for structured cycling training. It's used to establish training zones, ensuring that your workouts are tailored to your specific fitness level. By training in different zones, you can target specific physiological adaptations, whether it's building endurance, improving lactate threshold, or increasing VO2 max. FTP is also crucial for race pacing. Knowing your FTP allows you to gauge your effort and avoid going out too hard and fading later in the race.

Determining Your FTP

There are a few ways to determine your FTP. The most common method is a field test, typically a 20-minute time trial. After a proper warm-up, you ride as hard as you can for 20 minutes, maintaining a consistent effort. Your average power output for that 20 minutes, multiplied by 0.95, is a good estimate of your FTP. Alternatively, you can opt for a lab test, which provides a more precise measurement of your FTP under controlled conditions.

Of course, lab tests can be expensive, and it can be difficult to find roads that are straight, flat, and uninterrupted to make performing an FTP test reasonable. Fortunately, there are a number of online services that cyclists can subscribe to, such as Zwift and TrainerRoad, that offer convenient ways to test your FTP online.

Zwift:

• Ramp Test: This is Zwift's primary FTP test. It involves progressively increasing resistance until you can no longer pedal. It's a shorter test than the traditional 20-minute test, making it more manageable for some riders.
• FTP Test (20 min): Zwift also offers the standard 20-minute FTP test, where you ride as hard as you can for 20 minutes.

TrainerRoad:

• Ramp Test: Similar to Zwift, TrainerRoad offers a ramp test for a quicker FTP assessment.
• 8-Minute Test: This is a shorter test that focuses on your ability to sustain high power for a shorter duration.
• 20-Minute Test: TrainerRoad also has the traditional 20-minute FTP test.
• AI FTP Detection: This innovative feature uses your ride data to estimate your FTP without requiring a dedicated test. (Full disclosure, I am a TrainerRoad subscriber and have been using AI FTP Detection for quite a while). 

How Often Should You Test?

It's generally recommended to test your FTP every 4-6 weeks, or whenever you feel like your fitness has significantly changed. Consistent training will likely lead to an increase in your FTP, and retesting allows you to adjust your training zones accordingly. However, avoid testing too frequently, as this can lead to burnout and inaccurate results.

Beyond the Number

While FTP is a valuable metric, it's important to remember that it's just one piece of the puzzle. Other factors, such as your power-to-weight ratio, anaerobic capacity, and mental toughness, also play a significant role in cycling performance. Don't get too fixated on the number itself. Instead, focus on using your FTP as a tool to guide your training and achieve your cycling goals.

In Conclusion

FTP has revolutionized the way cyclists train and race. By understanding your FTP and incorporating it into your training plan, you can optimize your workouts, improve your performance, and reach new levels of cycling fitness. So, embrace the power of FTP and unlock your true cycling potential!