Ubiquitous in the pro peloton, power meters are becoming more common among enthusiasts and for good reason. The cyclist’s tool is the best way to measure effort, improvement and more.
Options in power meters have exploded in the last three years, with companies offering meters in cranks, spiders, pedals and hubs. Further, high-end smart trainers now come with integrated power meters to not only measure output but also regulate resistance for specific training.
Here are eight reasons why you should consider investing in a power meter,
1. Quantify effort
Think of a power meter like a weight scale. Installing one on your bike won’t magically make you faster, but it will give you a very accurate assessment of the state of things.
Without power, you only have soft metrics to use, such as RPE (rate of perceived exertion), heart rate (which varies with fatigue, caffeine intake and more) and speed/time (which is influenced by wind, your position and more).
Unlike running, where pace is the best indicator you have, in cycling, pace isn’t very helpful to determine the work your body is doing because there are so many environmental factors that affect it.
Power meters quantify the amount of power you are applying to the pedal in watts. Riding at 200 watts will always be 200 watts, no matter what your RPE, heart rate or speed is.
For example, when doing a steady effort at a given wattage, RPE and heart rate will at first lag behind and then climb. Conversely, if you did an effort and tried to keep your heart rate at a fixed number, your actual effort would at first be high and then slowly taper down.
2. Measure improvement
How do you know if you are getting faster or slower? Timing yourself up a hill is a pretty good method, but it isn’t foolproof. A good time could be more indicative of a strong tailwind than an increase in fitness — or testament to weight loss on your bike or body.
With a power meter, you have hard data to testify to short and long-term trends in performance.
Also, you don’t have to stare at your computer screen to learn from your data. In fact, you’re often better off focusing on your riding when on the bike, then looking at your data afterwards. Many easy-to-use software show your best power outputs over various periods (1sec, 5sec, 5min, 10min, etc.), so you can quickly skim over rides to see if you are getting stronger or more efficient.
3. Learn what works and what doesn’t
One thing I enjoy about riding with a power meter is that it helps me separate fact from fiction in terms of how I feel about an effort. For example, sometimes putting the bike into a bigger gear feels like I am producing more power, as the cadence slows down and I can really feel the strain in my legs. Often, however, the power meter will say, no, actually your power just dropped by 10w when you shifted.
While you can drown in all the various metrics out there, the basics are still the most helpful: power, cadence and heart rate.
With a power meter, you can experiment with different cadences (the speed at which you are pedaling) and see how that affects your power, your heart rate and your perceived level of effort.
4. Tailor training
Once you understand what your power output is for certain efforts — say, how much power you can steadily generate for 20 minutes — then you can start doing power-based intervals to improve.
Most training these days is based around something called Functional Threshold Power, or FTP. Coaches and riders alike will bicker about the specific definition, but basically FTP means the maximum power you can sustain for an hour.
Training software like TrainerRoad (or Zwift Workouts) is based on your FTP and training plans you can buy through TrainingPeaks or Today’s Plan also keys off this number.
5. Identify strengths and weaknesses
Each one of us is a mixed physiological bag. Some of us are great climbers, but lousy at sprinting. Some of us can time trial well, etc. By measuring your different traits quantifiably, you can see specifically where you can improve.
Relatedly, if you are training for a specific thing — say criteriums or cross-country racing — then you can focus on what is needed for that type of effort. We shouldn’t all be training like a 20-year-old preparing for the Tour de France, for many reasons!
6. Quantify total training load
You’ve probably read training articles warning you not to increase your weekly training by more than 10 percent. For runners, this is a fairly straightforward proposition: measure the miles and do the math. But we’re not runners. And 10 miles cruising easy in the small chain ring is not the same thing as a 10 mile time trial effort, is it?
Riding with a power meter, you can track your weekly workload through various software. CTL (chronic training load) is a metric on TrainingPeaks, based on your cumulative power output. Strava has a simplified version called ‘Fitness and Freshness’.
7. Cut out the junk miles
Perhaps you have unlimited time to ride and you can train all day, every day, if you like. Chances are, though, that you live on Earth with the rest of us and ride time is a finite resource. With a power meter, you can make sure you’re getting good bang for your buck.
This doesn’t mean you have to be a robot and stare at your computer. It just means that, with a little self-study, you can understand what types of rides are effective training and which are not.
8. Follow a power-based training plan — train with greater specificity and measure the results!
If all this sounds too complicated, then take heart: one of the great things about training with power is that it can actually simplify training and take a lot of the guesswork out of it.
If you are game for following a training plan — I’m a fan of using TrainingPeaks, personally — then all you have to do is follow each day’s directions. No guessing how hard to go or for how long, etc.
This will not only make you a better rider, but it can give you confidence and peace of mind that you are training effectively.