Going Beyond Threshold Power – The SYSTM 4DP Power Profile

With the advent of accurate, reliable smart trainers like the KICKR and SNAP, more athletes are taking advantage of the benefits of training with power. With that comes a greater focus on metrics like Functional Threshold Power (FTP). For the uninitiated, FTP is typically defined as the highest power output you can maintain for an hour. Many cyclists and coaches see FTP as the mother of all metrics, designing workouts and training plans around moving that single number up. Conventional thinking held that if you wanted to improve your threshold power, you should focus your training on threshold efforts.

The problem with that approach is that it fails to take into account the variation in how individual athletes produce power across a range of durations and intensities. Even athletes with the same FTP can have very different capabilities when it comes to pushing out watts above threshold.  This variation makes it difficult to design a one-size-fits-all training approach based on the single metric of FTP.

Think of the goal of a higher FTP as your destination. How far you have to go, and what vehicle is best suited to get you there, depends entirely upon where you are now.  Just because two athletes have the same destination doesn’t mean they’re starting from the same place. Even if the distance is the same, they may be taking totally different routes. One athlete may have to tackle unpaved roads and mountain passes, while another may have a straight shot down the freeway. Understanding where you are is the key to planning the best route. That’s why smart trainers like KICKR are so effective. They allow you to get real-time feedback on your power output and accurately track it over time. But you have to go beyond FTP and look at the other ways you put down power.

At Wahoo Sports Science, we use a comprehensive power test that measures not just FTP, but Neuromuscular Power (5-second power), Maximal Aerobic Power (5-minute power), and Anaerobic Capacity (1-minute power). This is the same test used by The SYSTM in their new Four-Dimensional Power™  platform(4DP). We call it Full Frontal and it reveals what an athlete is capable of across a range of efforts, as well as the important relationships between the different ways of producing power on the bike. Take, for example, Maximal Aerobic Power (MAP) and FTP.

Roughly equivalent to your power at VO2 Max, MAP is determined in Full Frontal by an all-out, 5-minute effort. In physiological terms, it represents the upper limit of your body’s ability to use oxygen to produce power. More than that, MAP also acts as a ceiling on your FTP. In other words, your FTP will always be below and constrained by your MAP.  While everyone’s MAP to FTP ratio is different, there are limits to how close—or far apart—they can be. When reasonably fresh, your MAP can’t be lower than 115% of your FTP.  You can do as much tempo and threshold work as you want, but until you increase your MAP, your FTP simply won’t go up.

On the other end of the spectrum, there are athletes with MAP values as high as 140% of their FTP.  Just as the ceiling can be too low, it can also be too high. Once your MAP reaches a certain level relative to FTP, it won’t increase until you establish a good foundation of endurance. It’s not just the numbers in isolation, but the relationship between them that’s important.

Take two athletes, both with the same FTP. One has a MAP that’s 115% of FTP and the other has a MAP that’s 140% of FTP. Both ultimately want to improve their ability to produce sustained power (think time trial or the bike leg of a triathlon). To achieve that same goal, one athlete will need to work on raising their MAP ceiling while the other will need to focus on building a better foundation. Despite their similarities, the same training approach wouldn’t be appropriate for both of them. A fitness test that just measures FTP wouldn’t reveal that key difference.

Knowing how you produce power across a range of durations and intensities is the first step in developing an effective training strategy tailored to your unique physiology. Accurate, consistent power measurement during training, coupled with a solid understanding of where you are, is the key to getting where you want to be. You are more than your FTP.