The Advantage of Training With a Power Meter
Why Do You Need A Power Meter For Cycling?
Power meters have been used since the beginning of time, but only recently did they become popular among cyclists. They allow you to measure your efforts accurately and precisely while riding, which allows you to train harder and better. However, there are some disadvantages with using them:
1) It takes time before you see any improvement in training results (at least not immediately).
2) There is no way to tell if you are getting stronger or weaker due to changes in workload.
So it’s hard to determine whether you need more rest or more training.
3) If you want to compare yourself against others, then power meters are useless because they don’t provide enough data points at the same level of intensity.
4) It’s difficult to get accurate data from a power meter.
Some manufacturers make claims about their products being “accurate” but that doesn’t mean anything unless you actually test them. Most companies just say that they are based on scientific principles, but there is nothing in writing or even in the manual that says exactly how these principles work. In fact, most power meters don’t even come with manuals!
5) Most of the power meters on the market are quite expensive.
So you may need to take out a second or even a third mortgage on your home if you want to buy one (or two or three…).
6) There is no way to check if your power meter is broken.
Most of them are sealed and non-repairable.
7) Power meters require an advanced level of knowledge to set up properly unless you want to pay for a technician to do it for you (at an additional cost, of course).
8) Every power meter works differently so you need to research which one you should buy before buying it.
If you still want to buy a power meter after reading the disadvantages, then you might be ready to spend a lot of money on something that you probably don’t need.
Think about it: would you rather spend $2000 on something that can make your training a little more accurate or would you rather spend it on new lightweight carbon wheels?
Answer: lightweight carbon wheels!
Of course, if you are like a lot of road bikers out there then you will most likely spend the money on a new power meter because it is “sounds” like a good idea. However, I have found that most people who buy power meters don’t actually use them very much (if at all).
So why waste the money?
If you really want to improve your fitness, then I suggest that you take up mountain biking instead. It is a lot more fun and a lot less expensive!
How Do You Determine How Much Watts Are Displayed On Your Power Meter?
All power meters work on the same principle: you ride your bike and it displays how many watts you are producing. However, you may wonder how to determine how much power (in watts) is being displayed on your own power meter since the number can vary quite a bit from one power meter to another.
For example, my Vector Power Tap shows anywhere from 400 to 500 watts when I am at 300 watts. But then again, it might also show 200 watts when I am at 800 watts. It just depends on the day and the way that I am riding. In any case, you need to know how your power meter works and what the average is before you can train with it properly and get the most out of your training.
My particular power meter is known as being “liberal” because it shows more power than what you are actually producing. As a result, I need to train at lower intensities than what most training zones recommend. Of course, this might be good for me since I have a lot of endurance and not a lot of sprint.
On the other hand, some power meters are “conservative”, which means that they don’t show as much power as what you are actually producing. As a result, you need to train at higher intensities than what most training zones recommend.
Whatever the case may be, you still need to use your power meter as a guide and not rely on it completely. For example, I can’t decrease my intensity if I am riding up a hill if my power meter is telling me that I am at threshold level even though this might not be the case. Instead, I have to use other signs such as how I feel and how fast I am going up the hills. Fortunately, you will learn these signs with experience.
One last thing: don’t get too frustrated if your power meter is not accurate all the time. As I said, you need to take other signs into account. With practice and experience, it will come in handy in helping you train properly even with an inaccurate power meter.
How Do You Use A Power Meter?
As with most new devices and gadgets, there is a learning curve when it comes to using a power meter. There are several different types of power meters (such as the ones that go on your bike and the ones that you wear) so I am not going to focus on specific models. Instead, I am going to cover power meters in general and what you need to know in order to get the most out of yours.
Some power meters are very simple to use since they come with their own bike computer (such as the Garmin Vector). All you need to do is set it up and then ride your bike.
Other power meters don’t come with a bike computer at all. Instead, you have to connect them to a compatible device such as a phone, an ANT+ watch, or another cycling computer that is capable of receiving power and speed data from external sensors.
In a later chapter, I will go into detail about how to connect your power meter and how to train with it. However, before you can do any of that, you need to make sure that your power meter is correctly installed and calibrated.
Calibrating Your Power Meter
The first thing that you need to do when you get your new power meter is to make sure that it is correctly installed and calibrated. Most power meters come with comprehensive instructions on how to do this however you can also find online resources that show step-by-step instructions for your specific power meter.
A word of caution: calibrating your power meter is not an exact science. There are a number of factors (such as tire pressure, road conditions, and even the temperature) that can make calibration difficult. However, these same factors also make your power meter less accurate in terms of measuring the actual power that you are producing.
In other words, calibrating your power meter properly is an ongoing process and requires some patience and a bit of experimenting. Don’t get discouraged if your numbers seem a little off at first; just keep at it and you will be golden.
You might be wondering why you should calibrate your power meter at all if the numbers aren’t going to be completely accurate. There are two main reasons for calibrating your power meter: consistency and accuracy.
As I stated, calibration will help you get the same readings on successive rides. This will make it easier for you to assess your performance trends from ride to ride. It will also make it easier to compare your numbers to others in the future.
Some individuals are perfectly content with riding using only their instinct and feel. That is perfectly fine. Others prefer hard facts and data when it comes to assessing their performance. This is where a power meter can help.
As I mentioned earlier, a power meter isn’t perfect but it does offer you hard numbers that you can use as a starting point when it comes to measuring your fitness.
As you train and race, you will get a feel for what these numbers mean in practical terms. For example, you may find that you can average around 275 watts for an hour when you are in top form. This may enable you to set a new personal record (PR) if the conditions are just right. However, this same PR effort may only earn you a finish time of 3 hours and 12 minutes if the weather happens to be bad that day.
Calibrating Your Power Meter For Best Results.
In my opinion, the best way to calibrate your power meter is to make the effort as realistic as possible. In other words, ride outside as long as possible (in whatever type of weather conditions are present) before you begin calibration. You should also perform this process after a hard training ride or race since your legs will be well-worked at that point.
Ideally, you should use a course that is as flat as possible since a measured slope (which your power-meter will provide) can be off by as much as 6% if the course itself isn’t completely flat. In other words, a course with a winning ascent of 8 feet per mile might actually be 13 feet per mile (a 33% difference).
You should also allow yourself at least an hour for the calibration process. Don’t rush things; take your time and follow the steps listed below.
You will need the following items to calibrate your power meter:
A fully charged smart phone with an internet connection.
A course that is free of traffic and free of stops (such as stop signs or red lights). This course should stretch out at least a mile and should be relatively free of turns. The straighter the better.
The weather needs to be relatively calm and consistent with clear markings (such as street stripes).
Begin by riding the course in a relatively easy gear (such as 27 x 25) at a normal pace. You are not trying to time yourself; you are just trying to get a general feel for the course. Ideally, you will have someone with you who can time this initial warm up process. If you are riding by yourself, just ride slowly and make your way around the course without stopping.
Once you have gone all the way around the course (and your partner has started timing you), quickly look at your power meter. It should display a number in the field of watts. Write this number down for future reference. You will need to know this number later so that you can compare it against other data.
Sources & references used in this article:
Accuracy of the Velotron ergometer and SRM power meter by CR Abbiss, MJ Quod, G Levin, DT Martin… – International journal of …, 2009 – academia.edu
Bicycle power meter by DJ Cline – US Patent 5,031,455, 1991 – Google Patents
Validity and reproducibility of the Ergomo® Pro power meter compared with the SRM and PowerTap power meters by S Duc, V Villerius, W Bertucci… – … Journal of Sports …, 2007 – journals.humankinetics.com
Training and racing using a power meter: an introduction by AR Coggan – Level II coaching manual, 2003 – Citeseer