4DP® & Fitness Tests FAQs

First Things First: Level Mode vs ERG Mode for Smart Trainers

Before we dig into our fitness tests, we need to talk about the difference between Level Mode and ERG Mode for smart trainers. This is pretty important if you want to get usable results. Go ahead and read this article first, then meet up back here. 


Q: What is 4DP?

Exclusive to The Sufferfest, Four-Dimensional Power® (4DP®) uses four key performance metrics—Neuromuscular Power (NM), Maximal Aerobic Power (MAP), Functional Threshold Power (FTP), and Anaerobic Capacity (AC)—to determine your rider type, identify your strengths and weaknesses, and create your comprehensive 4DP® profile. Most importantly, the app then personalizes all of the power targets to match your unique profile, making them more effective than those based solely on percentages of FTP.

Q: Can you tell me more about those four metrics?

Sure. Watch this:

Q: Why is this better than training with FTP-based workouts?

Most other training apps only use your FTP to set your power targets in workouts. For example, sprint efforts would be set at 200% of your FTP, while VO2 efforts would be calculated at 105% of FTP. The problem, however, is that FTP only measures your sustained, aerobic power. It doesn’t tell you anything about how well you can sprint, launch repeated attacks, or take a flyer off the front. Two athletes can have the same FTP but have very different capabilities at higher intensities. Training apps that just use percentages of FTP to set power targets are making assumptions about what you are capable of. 

4DP allows The Sufferfest app to know exactly what you're capable of and map every interval to the appropriate metric and at the right intensity. That means you’ll get the precise training load you need to get faster and without wasting a single pedal stroke. (Read more: FTP vs 4DP®: The Difference in Accuracy Explained)

Q: How are my workouts going to change using 4DP®?

Depending upon your rider type, your particular strengths and weaknesses, and the workout you’re doing you might notice significant changes in your targets or more subtle differences. To give you the most effective workout possible, 4DP® uses a different reference metric for each type of interval. Depending on where they are placed in a workout, short sprints may be mapped to your 5-second power (NM), while VO2 intervals may be mapped to your 5-minute power (MAP). If you’re a sprinter with an NM of 400% of your FTP, sprint workouts like Violator or The Shovel will feel very different as a 4DP®-optimized session. Your targets during the sprints will be higher, but ultimately more effective. If you’re doing an FTP or “sweet spot” workout you likely won’t notice much of a difference.

Q: Do I need to know anything about sports science to make this work?

No. We've done all the science for you. You just need to do the fitness test, Full Frontal, and then the app will do everything else for you to best optimise your workouts.

Q: What are rider types?

4DP® uses your complete power profile to identify which of six rider types best describes you: Sprinter, Attacker, Pursuiter, Time Triallist, Climber, or Rouleur. Your rider type reflects your specific, innate strengths and helps identify what kind of workouts you need to focus on to become a more complete, well-rounded cyclist. It's important to note that your rider type isn't an indication of how strong you are - rather it's a representation of your innate characteristics. For more information on rider types, check out this article.

Q: How is my rider type determined?

A: The app uses an algorithm to analyze your results from Full Frontal, taking into account the absolute values, your gender, the weight you entered in your settings, as well as the specific relationships between your Neuromuscular Power, Maximal Aerobic Power, Functional Threshold Power, and Anaerobic Capacity. You could have the same FTP as another cyclist but be assigned a completely different rider type based upon these other factors.

Q: Do I need any special equipment to train with 4DP?

Nothing more than you need for any other kind of cycling app workout. You just need 1) a trainer and 2) some way to measure power and transmit that power data to The Sufferfest app. That means either a conventional “dumb” trainer and a power meter, a compatible smart trainer, or a conventional trainer with an ANT+ or Bluetooth speed sensor configured for Virtual Watts. Need information about Virtual Watts? Check out our the Virtual Watts section in our Help Centre

Q: How do I get my 4DP?

There are three ways to get your 4DP® profile:

  • Estimated: When you sign up for The Sufferfest, we give you an estimated 4DP based on your answers to our on-boarding questionnaire. These estimates are exactly that -- estimates. They're good enough to get a few sessions in to learn the app, but you'll want to dial them in as soon as you can.
  • Partial: Our Half Monty fitness test gives you fully accurate numbers for your FTP, MAP and LTHR. If you're still running your estimated 4DP®, we'll also make new estimated for your AC and NM based on your results.
  • Full: Our Full Frontal fitness test gives you everything: FTP, MAP, AC, NM, LTHR. It will also assign you a Rider Type, identify your primary strength and weakness, and give you recommended workouts to develop your strengths and improve those areas of your fitness that need the most attention. Full Frontal also allows us to personalize your training plans to your  4DP® profile to ensure you get the most gains from the time you have to train.

Q: What is the Half Monty fitness test?

Half Monty is the most sophisticated and accurate ramp test of any training platform. More approachable—but less comprehensive—than Full Frontal, it includes a solid warm-up, a MAP-based ramp (our research shows this is more accurate than FTP-based ramps) and a sustained, sub-threshold Heart Rate effort (which is really pretty easy). This gives you far more accurate results than a 'standard' ramp test found on other apps. And unlike other ramps that only estimate your FTP, Half Monty gives you your FTP, MAP and LTHR.

Q: What is the Full Frontal fitness test?

More difficult—but more complete than Half Monty—Full Frontal is a comprehensive fitness assessment that measures not just FTP, but the four key ways cyclists produce power: Neuromuscular Power (sprint / 5-second power), Maximal Aerobic Power (VO2 / 5-minute power), Threshold Power (endurance / 20-minute power), and Anaerobic Capacity (one-minute power). Over the course of an hour, you'll get a thorough warm-up and then be taken through a specific sequence of four different maximum efforts. The Sufferfest app then analyses your results and generates your complete 4DP® profile, assigns you a rider type, and customises all training plans to your profile.

Q: Should I do Half Monty or Full Frontal?

  • Half Monty is the easy one. It's perfect for riders who have little to no testing experience or riders who are mid-training plan and want to check how their fitness is progressing. Just keep in mind that Half Monty gives you your FTP, MAP and LTHR. It does not give you accurate AC or NM numbers, nor can it calculate your Rider Type, Strengths, Weaknesses or adjust training plans to your particular profile.
  • Full Frontal is the comprehensive one. It's ideal for experienced riders who have done fitness testing before and those who are about to start or who have just finished training plan. Full Frontal is also for you if you want the full deal: FTP, MAP, AC, NM, Rider Type, Strengths, Weaknesses and personalized training plans.

Q: Do I need to prepare for these tests in any way?

  • Half Monty: You can pretty much do this test whenever you like as long as you are not feeling really fatigued. We wouldn't recommend you do it at the end of a really hard training week, but other than that, go for it.
  • Full Frontal: Because it requires four maximum efforts, it's important to be well rested for this test. It's worth it. Here's our recommendation on how to approach the Full Frontal: Read this and watch this:

Q: I finished Half Monty or Full Frontal and got a message that one or more of my values was automatically adjusted. Why is that?

The app uses well-documented ranges in human performance and physiological norms to validate your results from Full Frontal. For example, it’s physiologically impossible for someone to have a Maximal Aerobic Power that is less than 115% of their Functional Threshold Power, regardless of their fitness. If any of your four test results fall outside the normal range of variation for that value (either higher or lower), the app will alert you and automatically adjust your test results to a valid number. Reasons for an invalid result may include improper pacing or inconsistent power reporting. Pacing a fitness test like Full Frontal takes practice. If you’re concerned about your results, review the pacing strategies video and try Full Frontal again once you’re properly recovered. 

Half Monty uses a sophisticated validation algorithm to make sure you did the test correctly. On-screen prompts will help you get the most accurate result. If for some reason you didn't follow the instructions, we'll let you know at the end of the test and give recommendations for how to improve the accuracy of the test the next time you do it.

Q: My FTP from Full Frontal is lower than from other FTP tests. What’s going on?

After testing hundreds of athletes in his lab at the Boulder Center for Sports Medicine, Coach Neal Henderson found that for many athletes, their lab-determined FTP did not match up to the traditional 20-minute field test.  The assumption had been (and continues to be with conventional FTP tests)  that 95% of an athlete's 20-minute power is equal to their FTP. Unfortunately, it’s not that cut-and-dried. Two athletes can have the exact same 20-minute power, but produce that power differently. One may produce 97% of it aerobically, while the other may produce 93% of that power aerobically.  Assuming 95% of an athlete’s 20-minute equals their threshold power is the same as assuming everyone who is the same height has the same inseam.  Not only does this make the 20-minute power test imprecise, it also misses out on other important aspects of a rider’s physiology.

If you are a rider who is only producing 93% of your power during a 20-minute test aerobically, then that means you are drawing on other energy systems—either Maximal Aerobic Power (MAP) or Anaerobic Capacity (AC)— to generate that power. Instead of measuring your threshold power, the 20-minute test is really measuring multiple energy sources. That results in an FTP that is artificially high.  By measuring four distinct ways cyclists produce power, Full Frontal will be able to tell us where that additional power is coming from. A rider who is only generating 93% of their power over 20 minutes aerobically will often have 5-minute power (MAP) or 1-minute power (AC) that is well above average . Since the 20-minute test in Full Frontal comes after both the 5-second sprint efforts and the 5-minute test, you will not be able to hold the same 20-minute power in Full Frontal that you would in a conventional 20-minute test. Because of this, your FTP from Full Frontal is based on the full average of your 20-minute effort, rather than 95%. But to be accurate, you have to go all-out on the 5-minute effort that precedes it.

While this might tempt some people to go easy in the 5-minute effort to save something for the 20-minute effort, you need to keep in mind that the 4DP® power targets for workouts are based on all 4 metrics (and the relationship between them), not just FTP.  If you sell yourself short in one area of the test to improve another area, the training you do afterwards won’t be accurately tailored to your true abilities, and you will miss out on the real fitness improvements you are looking for!

Lastly, it’s important to remember that training is a means to an end. You train and suffer today so you can be faster tomorrow. Fixating on a single number at a single point in time isn’t productive. What point is there in having an artificially-inflated FTP if you’re not getting the right training stimulus out of a session? Since 4DP® takes all four metrics into account and personalizes all of your targets, you are ultimately going to get a much more effective workout, even with a “lower” FTP.

Q: Can I manually enter or adjust my 4DP® values?

Technically, yes. You'll find them in the Settings > Workout Settings part of the app. But unless you have an advanced degree in Sports Physiology, we don’t recommend it. It’s not just the individual values that are important but the relationship between them. Here are the rules for when and how to adjust manually or to ride Full Frontal again. 

If you feel like your values have changed during the course of a training plan, that's the perfect time to do Half Monty.

Q: My 4DP® values are different from the Badass Power Records in my passport. Why?

The Badass Power Records in your passport show your all-time highest power values for a given type of effort. The context in which you hit those numbers was likely very different from where those efforts occur in Full Frontal. The first 1-minute interval in Revolver is going to feel much easier than the final 1-minute effort at the end of Full Frontal. The sequence of the efforts in Full Frontal is as important as the type of effort that is being measured. As a result, you will most likely see power bests from other workouts that are higher than your results from Full Frontal.

Q: How often should I do Half Monty or Full Frontal?

  • Half Monty: You can pretty much do it as often as you like as long as it makes sense for your training. At a minimum, we'd recommend doing it when you first set up the app and then in the middle of any training plan you're doing. If you're not on a plan, then once ever 8 or so weeks would be a good way to approach things.
  • Full Frontal: You should do FF as soon as you're up for it to ensure you have a complete, accurate 4DP -- at the very least you should do it at the end of your first training plan (if you haven't done it beforehand). From that point, you should do it at the end of every training plan or 3-4 months if not on a plan (and if you're using Half Monty in-between to update your numbers).

Q: Does this change The Sufferfest training plans?

The comprehensive rider profiling Full Frontal provides means we can adjust every plan to accommodate your strengths and weaknesses.  Every training plan has a goal you are working towards, and each goal has different physiological requirements.  With Full Frontal, we now have a much better picture of your physiology and can adjust the plans accordingly to make sure you are targeting the areas you need to in order to achieve your goals. (Note that we can not adjust training plans based on Half Monty results. You'll have to do Full Frontal again to update your primary weakness, then apply the training plan again)

Q: This seems like the most awesome thing to happen to indoor training, ever. Am I right?


Check Out These Other Articles on 4DP®

How to Get the Most Out of Full Frontal

Learn More About Your Four-Dimensional Power® Profile

Learn More About Strengths, Weaknesses and Recommended Workouts 

Learn More About Rider Types


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