How to Conduct a Functional Threshold Power (FTP) Test

Power meters are becoming the new standard on bicycles today, especially for competitive athletes. They are certainly an expensive investment, but a worthwhile one if you’re serious about training with data.

Powermeter = LOVE!

Powermeter = LOVE (somedays)!

I’ve mentioned on numerous occasions that I have a love/hate relationship with my power meter. Heart rate-based training on the bike is a great training metric, but it can only do so much. I always liken my power meter to a truth-meter because it does not lie about my current bike fitness and riding abilities.

Power meters are extremely effective tools for training and racing. For long-course triathletes, like myself, I find my power meter acts as a governor for my bike leg because I know if I go out too hard, it will only be time until I blow up.

Most triathletes love spending money on new gear, whether we truly need it or not. A lot of triathletes want fancy race wheels because they make our bikes look fast and cool. Race wheels can easily set you back a couple of grand and the same with a power meter. Now if you had to choose between a power meter or race wheels, what do you choose? A power meter should probably be the correct answer and here’s why:

  • A power meter can help you build your engine. Sure, race wheels can shave a few seconds to a few minutes off your time, but an effective and strong engine (aka YOU) can shave even more time off your bike leg!
  • A power meter can help you monitor your efforts over time and keep you working within your correct zone. For example, if it is extremely windy out you will work harder (i.e. push more watts) than if there was no wind. If you have a power meter, you know you are working harder and thus not fight the headwind by pushing a faster pace (i.e. speed) like your competitors sans power meter.
  • A power meter can give you a highly accurate measurement of your bike fitness over a season. A power meter can be used for benchmark testing unlike a lot of heart rate testing that can have multiple variables with results.

There are various metrics that you can measure over a season with a power meter. I won’t get into that today because the terms can be confusing. If you work with a coach or train with a power meter regularly you are probably familiar with the terms such as normalized power, functional threshold power, critical power, etc.

Today I want to discuss Functional Threshold Power (FTP) because it is often used as the main benchmark testing for bike fitness.

Functional Threshold Power can simply be defined as the wattage an athlete can produce and maintain over a 1 hour time period without fatigue. FTP is relative to nearly all cyclists. It is important for an athlete to test their FTP at the beginning of their base training cycle to determine the correct training intensity zones and also to determine the benchmark for the season. Athletes should periodically re-test their FTP to compare against the benchmark test to observe fitness.


You might want a Puke Bucket!

You might want a Puke Bucket!


FTP Test Protocol:

  1. Warm-up: 20 minutes at endurance pace/easy to moderate pace; 3 x 1 minute fast pedaling (100+rpm) with 1 minute rest between; 5 minutes easy pedaling
  2. Main Set: 5 minutes all-out effort; 10 minutes easy pedaling; 20 minute time-trial
  3. Cool Down: 10-15 minute easy pedaling


  • Keep cadence normal (i.e. 90-95rpm) throughout the test
  • Pace yourself during the 20 minute time trial – it helps to break the time into small sections
  • If you are conducting this test outside, try riding up a steady climb or into a headwind

How to Calculate Your FTP:

  1. Download your data. TrainingPeaks is my preferred software program.
  2. Figure out your average power for the 20 minute time trial. In TrainingPeaks you can highlight the 20 minute interval and it will show average power for that time period.
  3. Take your average power number and multiple it by 0.95 for your FTP number.

Note: The reason you multiple your average power number by 0.95 is because you are subtracting 5% from it. A true FTP test would involve an athlete holding their highest average watts for 1 hour, but since most of us cannot focus that long, we shorten the test to 20 minutes. The 20 minutes is a shorter time period, and thus the athlete generally uses more of their anaerobic capacity and this skews the wattage data by about 5% over a 60-minute effort.

Now what? You know your FTP number and now you can use it to calculate your power-based training zones. The zones are below:

  • Active Recovery – Less than 55% of FTP
  • Endurance – 56-75% of FTP
  • Tempo – 76-90% of FTP
  • Lactate Threshold – 91-105% of FTP
  • VO2max – 106-120% of FTP
  • Anaerobic Capacity – 121-150% of FTP
  • Neuromuscular Power – N/A (maximal number of watts you can push for less than 30secs)

Most triathletes will train predominantly in the endurance and tempo zones, but it is important to include the other training zones in your training plan as well. A coach can help you better plan this type of work with your training plan.

It is important to periodically re-test your FTP to see improvements. If you don’t see improvement over time, it’s probably time to change-up your training routine!

~ Happy Training!

Book Review: The Powermeter Handbook


So I like to read if you haven’t figured that out. Especially about triathlon and exercise physiology related things. Yes, I am a total geek and I will own it! 🙂

Last April I decided to spend a lot of money to buy this little thing called a powermeter for my bike. Best investment ever! So in an effort to better understand what my powermeter tells me when I upload data to TrainingPeaks, I decided to invest in a couple of books. My first purchase was Hunter Allen and Andrew Coggan’s Training and Racing with a Powermeter. I excitedly told my coach about my purchase and she suggested that I read Joe Friel’s The Powermeter Handbook because it is easier to read and geared slightly more towards the triathlete. I have yet to read Allen and Coggan’s book, but it is in my ever increase stack of books to read. I’m current reading Joe Friel and Jim Vance’s Triathlon Science book. It was just released a couple of weeks ago and I am already over half way through it. Definitely a worth while investment if you’re a coach and/or serious athlete. And perhaps a total trigeek like myself! 🙂

One of my favorite quotes thus far in Triathlon Science is from Hunter Allen’s chapter on Triathlon Training Technologies. According to him “the powermeter does not lie, so workouts can be mentally challenging when fitness is not high as desired. Triathletes tend to be critical of themselves, so having a ‘truth meter’ on the bike might not be the best idea for hyper-self-critical triathletes (page 150). So fucking true. My powermeter is certainly my “truth meter.” I whined over and over again last year to my coach (and really anyone who would listen) about how crappy a cyclist I truly am. I always thought that I was a strong cyclist and easily finished in the top percentage of my age group, but through riding with a powermeter I learned that I completely suck at actually riding a bicycle. I was a gear-masher. My cadence was way too low. And I just plain sucked at riding consistently. We’ll talk about this at another time. Let’s get to the book review!

I’ve always been a huge fan of Friel. I like his writing style. It’s easy to follow and he explains things well. The book is divided into three parts: (1) what is a powermeter and how can it help me?, (2) how can I train more effectively using my power meter?, and (3) how can I use my power meter to improve my competitive performance?.


The first section was good. It discussed how a powermeter works. Exactly what I needed. So what is a powermeter and what does it do? Well, lets first answer why power. Training based on heart rate and intensity or rate of perceived exertion (RPE) is fine, but power on the bike is really the top dog. Most athletes believe that heart rate is proactive, but in fact it is reactive. It responds to what the muscles are doing. As Friel says, it is not the “engine”, but is simply the “fuel pump.” Friel points out that muscle is where nearly all the fitness changes take place and focusing on the rate at which the blood is pumped to the muscles is not the most effective way to train. Heart rate can also vary on a day-to-day-basis because of outside forces such as diet, race-day excitement, and psychological stress. Heart rate is also delayed meaning that if you are doing intervals then your heart rate will lag slightly behind the intensity pick up. Certainly heart rate is good to train with if that’s all you have. Speed is not the best way to gauge your fitness because obviously it varies on a multitude of factors, namely wind and hills. Feel or RPE is another method of training. Some people just prefer training by feel. It works for some, but for a majority of us, we prefer numbers. Most of us train by a combination of the above indicators.


So what is power? Friel defines power as “how much work you are doing and how fast you are doing it.” To physicists power is equal to work divided by time. However, in cycling terms we can define power as “power equals force times velocity.” We can break it down to “force is what you put into the pedals and velocity is how fast you are turning the pedals” (page 24). So power essentially tells you how much work you are doing at any given moment. As I mentioned above, powermeters are “truth meters.” A powermeter works by detecting force and cadence. Most powermeters have a magnet that is placed on a crank arm and a magnetic sensor on the frame or some combination of the above. Cadence is measured by how long it takes for the cranks to make one full revolution. Some do it electronically by measuring sine wave. Yeah, don’t ask me how. I only got a C+ in calculus. To calculate force, a powermeter has this thing called a “strain gauge” and is the most expensive part of the powermeter. According to Friel, “a strain gauge is a thin, flexible strip of material with a metallic foil pattern inlaid on it. As force (torque) is increased on the pedal, the strain gauge is very slightly stretched, thus changing the shape of the metallic foil pattern. When the pattern deforms, its electrical resistance changes. The amount of this change is an indication of how much force (torque) is being applied” (page 26). Okay Friel, I’ll take your word for it since physics is not my thang.


Friel then goes into describing the different training zones, etc. But, what really interested me was his section on economy. Economy is HUGE in Ironman training and racing and thus it peaked my interest because it’s relevant to my goals this year. Economy is a huge determiner of performance in Ironman racing. An Ironman is generally raced at about 70% of anaerobic threshold (AT), possibly less for triathletes new to the distance (as in Moi!). Obviously, 112 miles on the bike requires a constant pace and effort. Burning matches is an extremely bad thing and can lead to a horrible run and a possible DNF. A powermeter can reign in an athlete from doing stupid things.


Part two of the book gets more into the nitty-gritty stuff of the powermeter and training with one. The first chapter of this section is on power zones and how to determine your functional threshold power (FTP), which happens to be one of my favorite things to do. NOT! Power zones are very similar to heart rate zones: active recovery (zone 1), aerobic endurance (zone 2), tempo (zone 3), lactate threshold (zone 4), VO2 max (zone 5), anaerobic capacity (zone 6), and sprint power (zone 7). The primary difference between heart rate zones and power zones is that power zones are a percentage of the FTP instead of the percentage of maximal heart rate.


Friel tells you how to determine your FTP. Once you have calculated this then he tells you how to ride with intensity. The biggest thing that I learned about in this chapter was the variability index (VI). I knew a little bit about it via my coach who yells at me about my piss-poor VI. VI is the comparison of your normalized power and average power. What is normalized power? According to Friel it is the “average power normalized to reflect the metabolic cost or sensations of fatigue experience during a ride” (page 79). In other words, NP compares the range of variability of power during a ride with the average power of the ride. So if you ride inconsistently then your normal power will reflect this. It is actually telling you what the workout felt like. A perfect VI is 1.0, meaning that you rode very consistently at the same average power. If you a bad cyclist like me then your average VI for rides tends to be in th 1.15-1.25 range. I get a big fat F for my VI. My horrible VI tells me that I ride inconsistently and I often burn too many matches. My workouts feel a lot harder than they actually should be. This is very bad for Ironman racing. My big goal this is year is to learn to ride my bicycle better and work on having a “perfect” VI.


The most interesting thing I found in this book is Friel’s 50-40-30-20-10 Rule. The concept actually came from Alan Couzens, an exercise physiologist and triathlon coach. The essence of the rule is to conserve energy when the bike is going fast (i.e. downhills; think descend into Keene on IMLP bike course!) and expend energy when the bike is going slow (i.e. uphill; climbing the Three Bears). Friel then goes on to talk about this theory on burning matches. I highly suggest you pick up the book for these two tidbits. Burning too many matches = bad bad bad!


The remaining part of the book discusses how to design workouts using power zones and Friel gives examples of workouts for the triathlete at various distances and the cyclist for various sorts of races. Again, I suggest picking up the book if your interested in this portion of the book. Overall, I do believe it is a worthwhile investment if you have a powermeter. I certainly learned a lot about my powermeter and how it works. Friel doesn’t get super technical like I guess the Allen and Coggan’s book does; however, I think it’s great for someone like me who isn’t really a fan of calculus and physics. I still am looking forward to the Allen and Coggan book though. Friel’s book definitely answered a majority of my questions and also made me understand and connect the dots of why my coach assigns certain workouts for me. I’m very much a “why person” so I like to know the why behind everything. Yes, I was totally that kid who would constantly ask why. 🙂


Verdict: Buy the book if you have a powermeter!

~ Happy Training









I have the POWER!

Yes, I know I don’t have pedals on Azul. They are on my road bike (perhaps someday I will actually buy a second set of pedals!)

Two weeks ago Azul (my tri bike) got an upgrade, a SRAM S975 Quarq powermeter! A powermeter is something I’ve always wanted, but I wasn’t sure if it was going to happen earlier this year due to extensive car repairs, but I received an unexpected (well, maybe not really so unexpected) bonus at work and I decided to bite the bullet and purchase the powermeter. What also catalyzed the purchase was my need to switch from a standard crank (which came with my bike) to a compact crank due to my cadence issues and also I ride a lot of hills. BEST DECISION EVER! I feel much more comfortable and stronger on my bike now that it has a compact crank!

So, I got my Quarq about two weeks ago and my awesome bike shop put it on Azul for me. I got her home and put her on the trainer and tried syncing the Quarq with my Garmin computer. FAIL! No connection. Would not read at all! So, on Saturday I brought Azul back to the shop for troubleshooting. No bueno. Then I thought why not change the battery, even though this is a brand new powermeter and the battery should be fine, why not? I went to the store purchased the battery, replaced it in the Quarq, and BEEP “powermeter detected.” Seriously?! A new battery? Urgh, why did it have to be so simple!

Once Azul and I were home I put her on the trainer for my pre-long run easy spin. I made it 45 minutes before the new battery in the Quarq died. WTF?! Next morning I went out and purchased two new batteries at the grocery store. I put a new one in, the powermeter was detected for about 5 seconds, my Garmin succeeded to tell me that the battery in the powermeter was low and then finally died. Awesome! My Quarq was clearly defective and I was super upset. I tried calling Quarq, but of course, they are not open on Sunday. So, I emailed their customer service department to tell them about the issue and that I will be calling first thing on Monday morning! Later that afternoon I got an email back from Quarq (on a Sunday!)! On Monday they called my bike shop and decided to send me a new spider (the electronics part of the Quarq) because a Quarq that does not hold a battery charge is clearly not normal. I got the new spider in a couple of days and my bike shop put it on Azul by the end of the week. The new Quarq works flawlessly! I was very impressed with the Quarq/SRAM customer service. They were very professional and super fast! Thank you!

I’ve only ridden with my powermeter a handful of times so far, but I really like it. I’ve been reading various articles and watching webinars from TrainingPeaks about training with power. It is extremely effective to train with power on the bike and I know I will become a much stronger rider over time. My coach will now start giving my bike workouts in terms of power intervals compared to heart rate. This past weekend on my long ride I had some tempo and VO2 max intervals that were all written pre-powermeter and thus set to HR. I finally learned how to input my workouts into my Garmin Edge 800 so as I ride it just tells me what I’m doing so I don’t have to memorize my workouts. I set all my intervals for my HR zones, which turned out to be rather annoying because my Garmin would beep about every 5 seconds to tell me my HR was too high. Well, no shit, I just climbed a hill! But, I must admit, that I really love when I end a workout. My Garmin will “sing” a tune to let me know it’s over! It was rather amusing I thought.

I have my season opener triathlon on Saturday! I’ve decided to forgo my graduation ceremony to race the Tri for the Y in Freeport. It’s only a 325 yard pool swim, 13 mile bike, and a 3 mile run. It’s a short one, but my coach told me to go all out. I’m interested to see my performance. I have not done a sprint tri in almost a year and most of my training has been focused on long course, but I feel ready and I’m definitely itching to race. Two weeks from this Sunday is Mooseman 70.3! I’m still super nervous about this race. I think the main reason I’m nervous about this race is because I have high expectations for myself. I want to do well and I want to PR; however, from everything I’ve read and heard, this is not the race to PR on. At this point, my goal will be to finish in one piece and have fun. I definitely plan to push myself during this race, but my real “A” race is going to be REV3 OOB.

In other more exciting news, I have officially signed up to volunteer at Ironman Lake Placid this summer! You know what that means… 🙂

Happy Training!