I Did the Hardest Cycling Test (4DP) and Lived to Tell the Tale...
Yes, I am still alive, because I wrote this newsletter.
This morning, I did the 4DP cycling test, which is similar to a FTP (functional threshold power) test in that it measures your ability to hold power on the bike, analyze fitness, and calculate training zones.
But it’s also very different.
For one, it uses different mini-tests to provide a more complete picture of your abilities and strengths as a cyclist.
Before we get into how the 4DP test works, I should probably explain a bit about power and what FTP testing even means.
How and why we calculate power on the bike
Watts, FTP, lactate… If you’re new to triathlon training, the sheer number of terms is enough to make your head spin! So I want to define a few so it’s easier to understand.
Power is a measurement of energy defined in watts, just like a light bulb. Power on the bike is generated through force (the force you apply to the pedals) and cadence (how many revolutions your pedals turn in a minute).
For example, you might pedal at a low cadence of 65 rpm and produce 140 watts, which causes your bike to go 20 mph. You could also pedal at a much higher cadence of 90 rpm, produce 135 watts, and still ride at 20 mph. The first is more muscular effort, and the second is more cardiovascular effort.
Where power is different than metrics like heart rate or RPE is because it’s not influenced by outside factors like wind, temperature, terrain, whether you got a good night sleep, are feeling stressed out, etc. Power is real-time data on the work being done.
Power is used to set functional threshold power, much in the same way that max heart rate is used to set heart rate zones. This is done with a Functional Threshold Power (FTP) test. Traditionally, it involves a one-hour time trial where a cyclist rides at the power he/she can sustain for 60 minutes. Now this long of a test is very hard to pace properly (which can lead to inaccurate results). Also, it takes a lot of time to recover from, so you can’t repeat it as often.
Therefore, most athletes use a version of the FTP test with a 20-minute effort that provides an estimation of your FTP. Versions of this test are available in multiple platforms, like Zwift, Trainer Road, Wahoo, etc. Zwift also has a ramp test. This test estimates a rider’s FTP with a progressive build of one-minute intervals to exhaustion. So it will start around 100 watts and increase by 20 watts each minute until you can’t pedal anymore. The test is trying to determine your best one-minute power to extrapolate your threshold and training zones.
It works… but I’ve always felt that it wasn’t very accurate because it puts all cyclists into the same box.
To learn more about power, heart rate, and RPE, check out this post. Understanding the Triathlon Training Triad.
How the 4DP test is different than a FTP test
I like this quote from Wahoo Cycling, because it perfectly explains how the 4DP is different than a traditional FTP test.
“For years, cyclists have relied on a single number: Functional Threshold Power (FTP). While FTP is valuable, it tells an incomplete story. It’s like describing a car’s performance using only its fuel efficiency while ignoring horsepower, acceleration and handling.”- Wahoo Cycling
4DP stands for (Four-Dimensional Power), and each part of the test analyzes how your body can perform at different intensities and durations.
That’s why I really “like” the 4DP test. In the past, we’ve done the FTP ramp test and FTP ramp lite test on Zwift. And while it can be useful for setting basic zones, it doesn’t measure much beyond your ability to hold sustained power.
For example, I’m more of a diesel engine. I can push a pretty good percentage of my max power for long periods of time. But really higher power for short durations? That’s not my thing.
Matt, on the other hand, is more of a sprinter. He can push very high power for a short period of time. But he has a harder time holding a higher percentage of that power for longer durations. We all have different strengths as athletes, and the 4DP test helps to highlight the areas you’re good at and identify areas for growth.
Also, I think it gets you away from the obsession with a single FTP number, which as we know, doesn’t tell the whole story as far as your ability as a cyclist, and triathlete for that matter. In reality, an FTP test measures your ability to hold sustained effort, which is great, but there’s more to cycling than that. Also, I feel like the 4DP test might be better for triathletes because the 20-minute FTP portion is completed after you’re already fatigued from the previous max efforts, so it’s more applicable to real-world racing.
Wahoo defines the 4 power profiles this way.
Neuromuscular power- Absolute peak power output. Something you could sustain for only 5-15 seconds. This part of the test measures your explosive force and ability to recruit fast-twitch muscle fibers.
Anaerobic capacity- Reflects the max power you can sustain for roughly 1 minute while under fatigue. It’s called anaerobic (without oxygen) because at this point your body is creating energy through anaerobic glycolysis. This results in the creation of lactate, which causes the burning sensation in your legs.
Maximum aerobic power- This is also referred to as VO2 max, which is the point in your power output when your oxygen consumption plateaus. Typically sustainable for 3-8 minutes.
Functional threshold power- This is FTP, and it’s the max power you can sustain for about an hour, while in a steady state. Your body is operating somewhere between aerobic and anaerobic, which is why you can sustain the effort for longer, because the amount of lactate you’re producing isn’t exceeding the amount of lactate your body can clear.
My experience with the 4DP Cycling Test!
Here’s how I did the 4DP test this morning.
First, there was a 10 minute warmup. Then, I did 10 minutes as a build from z2 to z3. For me, I thought about progressing from Ironman power to half ironman power and just a bit above that. There was another few minutes of rest, and after that, the first test began...
Test 1- This part included a 5-second all out sprint, followed by 2 minutes easy. Then, another 5-second all out sprint and another 2 minutes easy. This part wasn’t too bad at all, but I did find it hard to get my gear selection and cadence up to a “sprint” that quickly since it’s not something we typically do on triathlon bikes. I think I would’ve been better at a 10-15-second sprint.
After a few more minutes easy rest, it was time for test 2.
Test 2- This part included a 5-minute best effort. It was very important not to hold back and to give it everything I had for five minutes. My coach said I would know if I was riding at the appropriate effort level if I got to 2.5 minutes and wasn’t sure I could make it another minute. This was probably the hardest part of the test for me.
After a 5-minute easy spin, it was time for test 3.
Test 3- This is a traditional FTP test of 20 minutes, best effort. It’s a bit harder to pace, because the time is longer, so my coach suggested that I look at the power I held for the 5-minute best effort and take 80% of that. Then, I should try to ride around there for 10 minutes and see if I could hold that or increase during the last 10 minutes, giving it every I had in the final minute.
I texted Matt, who was upstairs doing strength, just to make sure I was calculating percentages properly when I saw that number… But I surprised myself! I felt pretty strong for the first 10 minutes, like it was harder to sustain the power at 15 minutes, and a bit sickly by 17 minutes, so I think that was the appropriate effort level.
After another 5 minute easy spin it was time for test 4.
Test 4- This was 1-minute, all out, as hard as you could go. After facing the 5-minute and 20-minute tests, this seemed like it would hurt, but be over quickly. You’d be surprised at how long a minute takes though.
That’s it! After a 10-minute cool-down, I had successfully (I think) completed my first 4DP test. Then, I headed out for a 20-minute brick run, at the beginning of which I felt like I had wobbly baby giraffe legs, but everything loosened up as I kept running, which I think was the point.
Have any of you done the 4DP test? If so, what did you think was the hardest part?
I want to conclude this newsletter with a note about performance tests. It’s important to realize that tests do not define your abilities as an athlete. Yes, they are helpful for setting training zones and highlighting strengths and areas for growth, but your identity as an athlete can’t be defined by a number, or a single test for that matter.
My advice is to go into them with an open mind. Let go of expectations. Aim for good form and execution. Fuel your body well in the days prior with good food and adequate sleep. And give it your best effort.
My coach likes to call these “checkpoints” instead of tests to underscore the importance that there is no pass or fail with fitness testing and that the results, whether good, average, or otherwise, don’t reflect on your ability as an athlete.
For example, some athletes aren’t very good at testing. They get anxious and worried about reaching that type of intensity (hello). Other athletes find it hard to push themselves in a training environment, and they perform better at races.
Also, a test shows what you can do on a single day. If you tested every week (which you would never do) you would likely get different results each time. Also, the more often you do a particular test, the better you get at executing it.
So far this week I’ve done the swim test and cycling test, so you can guess what I have coming up this weekend…
Say a prayer for me.