Power Up, pt 1: The Book
Dec 2, 2011
article & images by Nick Salazar
Dr. Andrew Coggan is one of the co-authors of Training and Racing with a Power Meter, along with Hunter Allen. He has been working with ergometers (power meters) for three decades, and it's safe to say he knows his stuff. He was kind enough to answer some questions to go along with this article
TriRig: Dr. Coggan, thanks very much for talking with us. I understand you've been working with power meters since the early 1980's. That's about as long as the current generation of distance has been alive. What was the power landscape like back then, and how has it evolved in those three decades?
Dr. Coggan: I was actually introduced to the idea of "training by power" in 1977, when Dr. David Costill was kind enough to write an ergometer-based 12 wk winter training plan for me. From that point forward I did a lot of my training on ergometers, especially once I bought a Schwinn Velodyne trainer in 1989 and could use my own bike. In 1996 I got the chance to borrow an SRM for a few months, and in 1999 I became a pilot user for PowerTap and finally had regular access to power data while cycling outdoors.
In terms of what has changed, clearly powermeter use is a lot more common now, which is due in part to lower costs and more options. More importantly, though, I would say many more people now understand and appreciate the significance of power as a metric by which to evaluate the efficacy of an athlete's preparation program. That in turn seems to have had a significant impact on how at least some people actually train, even though the basic principles of exercise physiology (e.g., overload, specificity) have long been known. In short, now that people have a way of readily measuring what they are trying to achieve, it is far easier to determine which approaches or practices contribute to that goal, and which do not.
(Note that I've previously attempted to summarize the history of powermeter use in cycling in a blog post that can be found here).
TR: The market for cycling power meters has exploded in recent years, with both a variety of offerings, and a variety of measurement techniques. Which innovations in the last couple years do you see as being the real winners? The pick of the litter, so to speak?
Dr. Coggan: I'm not sure that I would call it a "real winner", but obviously the ANT+ wireless protocol has had a big impact, for better or worse, on how manufacturers approach things. Unfortunately, in many cases I think that new product design has been driven largely by market forces, i.e., by the need to turn a profit, rather than by what end-users really need, which is a simple, reliable, accurate, and precise tool for measuring power.
To give a simple example: at least when using a strain-gage-based powermeter, probably the most important common action required of the operator to assure quality data is that they properly set the zero offset. Yet, in too many cases this requires digging through multiple menus on the head unit, or manufacturers have instituted a "black box" automated procedure that may or may not always do what it is supposed to do. That absolutely should not be the case.
The above speaks to offering currently on the market. As for what is still in the pipeline, the Garmin Vector pedals obviously have the potential to provide data that was not previously available, but at this stage it is hard to say what, if any, impact that will really have. I suspect that the system will actually prove to be more of a step forward for scientists interested in studying pedaling dynamics than for cyclists/triathletes interested in winning races.
TR: The gear heads in our audience will love to know what you're personally using on a daily basis to measure your own power. Can you tell me the power meter, head unit, and software that you're currently using?
Dr. Coggan: I'm still using the wired SRM Pro track and road cranks that I bought new and used, respectively, in late 2001/early 2002. Prior to that, I used PowerTaps for a couple of years, but wanted to be able collect data in UCI-sanctioned races (no wheelcovers allowed) and also got tired of sending things in for repair every few months. I've also trialed Ergomo, iBike, and Quarq powermeters for various periods of time, but none of them proved capable of providing the same robust data and user experience that I get with the SRMs. The Ergomo, for example, was clearly non-linear even during one-legged pedaling, and also only measured the power of my left leg and doubled it to estimate my total power. The iBike was reasonably accurate on average, but was often high or low over shorter durations (i.e., seconds/minutes instead minutes/hours), couldn't be used indoors, and required too much "care-and-feeding" for my preference. Perhaps not surprisingly (because they both use strain gages placed in the crank), the Quarq came closest to the SRM, but had problems accurately calculating power when cadence was changing rapidly, and the lack of ready control over the zero offset and slope values meant that I couldn't have complete confidence in the data.
,br/> In terms of head units, I use a PowerControl V, but still keep a couple of older PowerControl IVs (with badly faded displays) around for when I need to collect data more often than every 0.5 s. Finally, in terms of software I naturally use TrainingPeak's WKO+ 3.0 for routine analyses, but still often export the data for manipulation in a spreadsheet for more advanced analyses.
TR: Getting down to the book itself, let's talk about how it relates to triathletes. In general, I've tried to compress the most salient points of your 326-page book into just a few paragraphs. Obviously that won't do the book justice, but is there anything you'd like to add or change with regard to my summary?
Dr. Coggan: No, I think you've summed things up quite well: despite the pleasure people like me get from torturing the data, the fact of the matter is that you can learn many valuable lessons by taking a much simpler approach, at least initially. As you point out, that's especially true for triathletes, whose power over short durations has little impact on their overall performance.
TR: Greg LeMond is famous for once having said about cycling, "it never gets easier. You just go faster." To what extent is that true about training with power, and to what extent does adaptation mean that, for example, your FTP-level efforts will feel any easier?
Dr. Coggan: Regardless of whether you train with a powermeter or not, I think that as your cycling fitness/prowess improves, it doesn't get any easier, it is just hard in a subtly different way. I say this based on my own personal experience with TTing at moderate altitude, where the reduction in absolute power reduces how hard I feel like I'm pushing down with each pedal stroke, while at the same time my muscles "burn" just as much or more compared to sea level, I'm breathing just as rapidly, etc. In this context, altitude can be viewed as causing an acute reversal of some of the training-induced increase in power, which occurs over a much longer period of time such that it is more difficult to really keep track of your perceptions. As I tried to emphasize above, though, it is a very subtle difference, and I can't be 100% certain that I'm not imagining things (since I know the physiology a priori).
TR: (Before this interview, I did an FTP test to ascertain my own threshold power, and sent the power file to Dr. Coggan for analysis.) Let's take a look at my FTP test. I did this test on an indoor trainer, according to the workout prescribed in Chapter 3 of the book. How do things look?
Dr. Coggan: For one of your first sessions using a powermeter it looks fine. Of course, the more experience you gain the better you get at pacing such things, which is especially important in light of the 5 min "leg opener" effort that is part of the test protocol (note: the method for determining functional threshold power described in Chapter 3 of our book is really my co-author's, Hunter Allen's, not mine. It isn't one of my favorites, in part because of the variable impact that 5 min effort can have on the subsequent 20 min, and in part because in the end you still only end up with an estimate of functional threshold power anyway. I have the luxury here, though, of not actually being a coach, and thus not having to deal with numerous athletes for whom I'd like to have some idea of their functional threshold. If I were a coach like Hunter, I might very well sing a different tune).
Of course, as we've discussed offline another consideration here is the fact that you did the test on an indoor trainer, which may (or may not) mean that your true functional threshold power has been underestimated. You'll get a better feel for that, though, once you've had the chance to train (and race!) outdoors with your powermeter (as I've said many times, one advantage of using a powermeter is that training is testing and testing is training).
TR: For those training without a coach, what's the best way to keep things simple - to better understand their training without having to track a plethora of numbers and metrics? Or is it better to simply get a coach if you aren't willing to pore over the data to a certain degree?
Although an experienced coach can certainly help "speed up the learning curve" when it comes to training and racing with a powermeter, having one is clearly not a necessity. What is important, though, is that you "keep your eyes on the prize", i.e., that you focus on your ultimate goal (i.e., to increase your power over durations relevant to your chosen event), and avoid getting sucked into the "paralysis by analysis" syndrome. If you can do that, then over time what initially seemed quite complex will eventually seem rather simple, and you'll be ready to progress to even deeper levels of analysis and, hopefully, insight/understanding. At the same time, though, you should make sure that you don't miss out on opportunities to learn something important just because you're not ready, or don't think that you're ready - in particular, this means making sure that your powermeter is properly calibrated from day one, that you check and, if necessary, adjust the zero offset before each ride, that you always download your data, etc. That way you'll already have a large database at your disposal when you've grasped a new analytical tool (or someone invents one) and you're ready to apply it to your own data.
TR: Any parting words for our readers?
Dr. Coggan: Yes: enjoy the ride!
TR: Thanks again, Dr. Coggan. Your help is invaluable, and I really appreciate your time.