Learn More About The 4DP Workout Rating System
With the release of Four-Dimensional Power (4DP™) you now have unprecedented insight into who you are as a cyclist. Instead of relying on the single metric of FTP, you can see exactly what you're capable of across a range of efforts: Neuromuscular Power (NM), Maximal Aerobic Power (MAP), Functional Threshold Power (FTP) and Anaerobic Capacity (AC).
We've updated the descriptions for all the workouts in our extensive library so that you'll see a section detailing how effective the workout is at building NM, MAP, FTP, and AC on a scale from 1 to 5 bars.
This ranking system goes beyond simply identifying which power metric a given workout references. It takes into account how long the intervals are, the intensity of the intervals, the target cadence of the intervals, the amount of recovery between them, how much you get to recover, and how fatigued each interval should leave you.
Just because a certain workout features short, high-intensity intervals doesn't mean it only trains your NM or AC. It's the relationship between the metrics, and which metric we're referencing behind-the-scense, that ultimately determines how a workout ranks across the four power types. Two workouts that at a glance may seem to have similar graphs can work very different systems depending upon a host of variables. The ranking system allows you to easily see what each workout has in store.
The Four Power Systems and What They Mean
Cyclists produce power in different ways, depending upon the duration and the intensity of the effort. There are four primary power systems:
Let's dig a little deeper:
These are maximal efforts that require maximal coordination. NM is about more than just explosive power. It's about having a smooth, efficient pedal stroke that allows you to recruit all of the muscle fibers in your legs and have them fire in the correct sequence. Sessions that build NM can range from all-out sprints to specific drills that focus on perfecting your form at both low and high cadences.
Your Anaerobic Capacity (AC) is a function of two variables: the size of your anaerobic “fuel tank” and how quickly you can refill that tank. To improve your AC you need to focus on short, intense efforts that drain your anaerobic tank, with recovery periods that are short enough such that the tank is never allowed to completely fill back up.
Maximal Aerobic Power:
Maximal Aerobic Power (MAP) represents your aerobic ceiling: how effectively you take in oxygen and use it to generate power aerobically. You can raise your aerobic ceiling a number of ways, but the most common method is to get to the point where you feel like you're breathing through your eyeballs, and then hold on for dear life. Workouts as diverse as Revolver (which features 1-minute efforts with equal recovery) and A Very Dark Place (which tortures you with 4-minute efforts) are great for building MAP.
Functional Threshold Power:
FTP is that fine line between a pace you can hold all day and one that makes you wish you could lay down somewhere soft to catch your breath. FTP is equated with pure endurance. Just like the other metrics, there isn't a single workout that is 100% effective at increasing it. Since FTP represents the tipping point, the "threshold" that divides low and high-intensity efforts, you can use workouts that have you sitting right below or right above your FTP to help drive it up.