Over the last few years you have probably heard a lot about power meters and how cyclists are using power to train. We all know that cyclists produce power when we ride, but why is that useful to us? As an everyday cyclist, why is power important? And, most importantly, what is a power meter?
What Is Power?
Power is a measurement of the work the cyclist is doing, and it’s measured in watts. Power meters use small sensors called strain gauges to measure the amount of power, or watts, you’re putting into the bicycle to make it move forward. The sensors send this information to your cycling computer, which gives you a read out of your power stats. There are a few different kinds of power meters, and each have their pro’s and cons.
- Real Wheel Hub Power Meters, which place the strain gauges in the driveside of the rear wheel. Generally this is the simplest type of power meter to install and use, since all you have to do is replace the rear wheel. They are fairly accurate, but generally can’t give you some of the finer points of power measurement, like if you’re generating more power with your right or left leg.
- Crank Power Meters, which place the strain gauges on the crank spider. These power meters are a little trickier to install, since they involve replacing the entire crankset and sometimes the bottom bracket. They are also more expensive, but some experts argue that they give a more accurate picture of power output, since they are closer to the source of the power output (your legs) than the rear wheel.
- Pedal Power Meters, which place the strain gauges in the pedal spindles. These are probably the most accurate power meters available, since they can measure directly how much you’re pushing and pulling with each foot—and they can also tell you if you’re power output is unbalanced. Another advantage is you can swap them from bike to bike or travel with them fairly easily.
Why Is Power Important?
Power is important because it gives a more dependable measure of your fitness and your ability. Average speed is ok, but it’s too dependent on variables like wind, how hilly your route is, etc… and doesn’t really tell you how hard you’re working. Heart rate is fine, but again it’s too subject to variables. Don’t believe us? Try strapping on a heart rate monitor and then think about your heart rate. We’ll guarantee you it goes up. Heart rate also doesn’t really give you a complete picture of what’s going on, since a high heart rate doesn’t always translate into increased work. This isn’t to say that these training tools are without value. Heart rate and average speed are both very valuable indicators of your fitness, and have a place in any cyclist’s arsenal. But unlike these other, more mercurial, measurements, power is a raw measurement of how much energy you are putting into the bike at any given moment. Even if it’s a terrible day, with the wind against you, and some vicious hills that produce an average speed that makes you want to hang your head in shame, you will still get consistent power readings that will tell you the true effort you were putting into the bike.
Training With Power
Training with power is also an improvement over old methods, because it yields more consistent results. You can’t really train to lower your heart rate—it just happens as a natural byproduct of becoming more physically fit. But you can train to improve power. Training with power opens up a whole can of worms that will be the subject of future blog posts, but there’s some rough things to know.
When training with power, there are generally two important numbers to look for: maximum power output and maximum sustained power output. Maximum wattage output is a measure of your all-out, everything you got power. Generally, you can’t sustain this for more than a few seconds—think the end of a sprint. This is the maximum amount of power you are capable of transmitting into your bike. The second number, maximum sustained power output, looks at how much power you can put out for a prolonged period of time. Generally riding at this threshold should be uncomfortable, but doable—think slogging up a long hill or mountain. There are specific tests you can do to find out each number, but we’ll get into that in another post.
No matter how long you’ve been riding, or what your end goal is, a power meter is the best way to help you improve your training. We have plenty of options for you to choose from, and for almost any budget.