A Hot Topic… Should I buy a Power Meter?

Over the last year, when discussing training gear with friends, the one piece of equipment that seems to always come up is the power meter.  Many people I know, myself included, seem to be going back and forth on whether it’s necessary to get one.  After investing in all of the “cool” looking stuff over the last year that’s supposed to aerodynamically make me faster I decided to sell my road bike and use the proceeds to invest into a power meter.  No, I haven’t actually done it yet but I’m currently weighing my options on what to order and am hoping to be training with one before the start of the New Year.  I thought I’d share my thoughts on why I’ve decided to get one and some of the info I’ve picked up along the way in researching the devices and their purpose.

For those of you that don’t know what a power meter is, it’s a device that measures your power output when riding your bike.  If you’ve ever ridden a stationary bike in a spin class it likely showed the watts you were producing when riding in class.  A power meter does the same thing except it measures this on your road bike or whatever bike it is you have it set up on. 

The next natural question I guess is “why do I need to know what my watts are”.  Watts are the measure of your power output.  By measuring and tracking this information it can tell you and your coach a lot about your training and racing.  It can show you how well or how poorly you paced yourself, how much effort you spent climbing Cypress or what kind of progress you’ve made in your training over the last 3 months.  It’s very similar to the information you would gather wearing a heart rate monitor as they both measure your effort level; however, a heart rate monitor, unlike a power meter, can be affected by outside influences.  If you’re feeling anxious or the weather is hot that day it can have an effect on your heart rate.  Another issue with training by heart rate is there’s a lag between an increase in effort and your heart rate increasing.  If you’re performing 5 x 1 minute intervals while spinning and you supposed to be keeping it to a certain heart rate level, chances are you won’t know if you’re going too hard or too easy as your heart rate will probably take 50 seconds or more to increase to match your current level of effort.  The same goes on race day, you may not notice that you’re going way harder than you’re supposed to climbing McLean Creek Hill before you’ve already burned a match.  Even though it was a 90 second effort climbing too hard by mistake, in an Ironman distance race you may be paying for that later.  And lastly a heart rate monitor doesn’t easily tell you if you’re making progress in your training, it only tells you how hard your heart is pumping.

Power meters aren’t for everyone though, and by no means are a necessity.  It was interesting looking at some of the Pro bike setups at Kona this year.  Andreas Raelert had no interest in looking at his power numbers during the race but for analysis purposes they still put it on his bike.  It was kind of funny seeing a bike computer strapped to a seat post.  Sometimes people just prefer to go by feel, or sometimes people can’t be bothered to track all this info and upload it onto a computer after every workout and there’s nothing wrong with that.  I don’t see a point in getting one though if you’re not going to consistently use it for pacing training efforts, monitoring progress and retesting every once in a while to adjust training zones.  In order to take full advantage you have to have your coach on the same page so that he can communicate to you what training zones he wants you in during your training session, otherwise those numbers on your computer screen are just going to be gibberish and not much use.  If used properly though power meters can provide huge benefits (from what I hear anyways!).

Now before I move on, I don’t want you to get the impression that I think training with a heart rate monitor isn’t useful.  I find them extremely useful, particularly for training on the bike.  I began using a heart rate monitor near the end of 2011.  I did some testing with my coach, Sean Clark, to figure out what my Lactate Balance Point was.  I won’t get into what that is because it’s a whole other topic, but what it helped us figure out was appropriate training zones.  It completely took the guess work out of how hard I should be going on recovery rides, how hard tempo efforts should be and where my heart rate should be to appropriately pace myself in races of different distances.  It took a little trial and error with the racing, but it helped me a lot in learning about proper pacing.  I can honestly say that there’s no way I would have had the race results I did, particularly in Ironman, if I hadn’t used a heart rate monitor CONSISTENTLY in training and in racing. And did I mention, heart rate monitors are actually affordable!  So why mess with a good thing?  I figure using a power meter this year will help me fine tune my training efforts, race pacing and contribute to getting my bike fitness to the next level.

The next question is what type of power meter to get as there are various options.  The biggest reason most people don’t ride with power is the high expense.  An SRM crank based power meter will set you back $2,500-$4,000.  I won’t even bother getting into those.  The two best options I see on the market right now are Powertap hub power meters and Quarq crankset power meters.  Both have their pros and cons.

An entry level Powertap hub will set you back $899 which is on the economic side of the spectrum.  You will have to get it built into a wheel or you can purchase one pre built into a wheel set.  Powertaps are very accurate with a claimed accuracy rating of + or – 1.5% and are very versatile in the sense that you can swap it between bikes.  The downside to this is if you have two sets of wheels, one for training and one for racing, you’ll likely need to buy a second Powertap to have built into your race wheel so that you have it for race day.

Quarq cranksets start at $1,795.  The base model is also very accurate with a claimed accuracy of + or – 2% and you don’t have to worry about swapping out wheels as the power meter is built into the crank.  Where having a crank based power meter falls short is that you can only have it installed on one bike.  If you have a rain bike you use in the winter it’s going to be a hassle to get it installed on that for the winter and then reinstalled on your prized possession come the better weather.  And that’s only if the crank set is compatible with both bikes.

After doing a little more research I’m leaning towards the hub based choice.  Don’t hold me to it as I haven’t ordered it yet but I have a funny feeling some people I know will finally succeed in convincing me to try cyclocross next fall.  I like the idea of being able to swap my power meter onto another bike and considering the cost of two compared to a crank based model it will only be a little more but I’ll have much more freedom with switching it between bikes.  I should also mention that there is another option that is scheduled to come out in 2013 called the StageONE.  It’s built onto your left crank arm and was on display at Interbike in September.  It’s apparently going to start at as little as $699 and be accurate to a claimed + or – 2%.  It will be very exciting to see the market for power meters become a little more competitive and hopefully A LOT more affordable.

For those looking to get a bit more info or are seriously considering investing in one of these I strongly suggest picking up a copy of “Training and Racing with a Power Meter” by Hunter Allen and Dr. Andy Coggan.  The book is a fantastic read if you’re interested in power meters and will be a huge point of reference when I start training with one.  They pretty much cover everything there is to know from describing the different types, their uses, testing your fitness level with them, how to use them effectively to acheive your goals and they also include a large number of workouts.  This probably only scratches the surface on what the book’s about but to sum it up it’s a great book and worth a read even if you’re not considering purchasing a power meter.  Once I get my hands on a power meter, do some threshold testing and try it out in a few training sessions I’ll write up another post and share my thoughts.