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.
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.
FTP Test Protocol:
- 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
- Main Set: 5 minutes all-out effort; 10 minutes easy pedaling; 20 minute time-trial
- 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:
- Download your data. TrainingPeaks is my preferred software program.
- 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.
- 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!