Power Meter to Self: "Dope!" – or, What I Learned From My Power Meter

Dede G hammering with her SRM power meter
Dede G hammering with her SRM power meter

Here’s a quiz: Joe Trigeek has a sleek new cutting-edge carbon tri rocket, and he has his fit totally dialed in (by TTBikeFit no doubt…). What should he spend his next paycheck on? A: a pair of blinged-out race wheels B: A training camp C: Mortgage, food, utilities D: a power meter?

OK – the title gives it away, but yes a power meter should be the next big expenditure for any serious triathlete once the bike is dialed in. In fact, I could argue that if you have a good fit on your current bike, even if it isn’t the latest and greatest wind tunnel spawn, you should get a power meter before acquiring said carbon sled. Yes I know most of us can’t resist the black-hole-esque pull of that ultra sexy frame. But we probably should if we don’t yet have a boring old power meter.

After 18 years in the sport, I finally got a PM this Spring (a Quarq ). And I am hear to tell you, riding with one is eye-opening. I learned some lessons in the first few rides that I had failed to acquire in nearly two-decades of racing. And it wasn’t as if I hadn’t trained with power before. I’ve had a Computrainer for 14 years, and now have about a dozen in our TriFitLab. But I hadn’t ridden on the road with power. Just the usual speedometer, heart rate (which I usually don’t bother with), and my own distorted perception of effort.

I am going to skip to the bottom line right now. A PM will TEACH YOU HOW TO RIDE SMART. My 18 years of tri-ing have taught me how to ride DUMB. Having spent several years doing a lot of sprints and Olys, I know how to hammer at threshold and beyond. Problem is, this doesn’t work well in long course. In fact, it may not even work well in short course. If all you have is your speedometer, average speed, heart rate and your own perception of your effort level, you are probably at a big disadvantage to that guy with a PM.

All of those, other than power, are indirect, delayed, imprecise, even misleading measurements of how hard your body is working. Except maybe your own ability to judge your exertion. But before you decide how good you are at perceiving effort, ride with a PM. Prepare to be enlightened. I certainly was. It’s funny how “easy” it is to put out 150% of your threshold power on a steep climb. Translation: how easy it is to burn a few matches. And when they are all burned, you’re toast. Probably somewhere in the middle of the run.

Look at car ads – especially for sporty autos. I guarantee the maker will trumpet the horsepower prominently. You should know your horsepower too – only the units are changed to watts as displayed by your power meter. With simple tests you can determine your functional threshold power, or FTP = the max power you can generate for an hour (and you don’t need to do a 1 hour test either – as little as 20mins will suffice). Once you know that, you can suddenly raise your training and racing IQ to genius levels, by basing your training and racing off of percentages of your FTP. And although the degree of geek-out opened up to you once you have a power meter is shocking, you really only need to know a few things to get tons of value out of it, even an unfair advantage.

But back to my own enlightenment. On the very first ride I realized that in the average race with rolling terrain, I have been SMOKING myself on the climbs. Riding like a big DOPE. And the worst part is, it wasn’t even making me faster on the bike, just shredding my legs. In the old days of short races I could get away with that to some degree. In 70.3 and longer, the redline gremlin WILL pay you a visit – sure he may wait a while, but sooner or later he’ll show up and pull the rug out.

I already knew my FTP power from the Computrainer. To my amazement in the middle of your average 6% hill I was blasting out 130-150% of FTP while my stupid perceived-effort meter (i.e., brain) was being overly-influenced by my single-digit speed and telling me that I was loafing. Then on that slight flat with a bit of tailwind, my brain sees 30mph and tells me that I better chill, or I’ll blow. WRONG! 180 degrees, bass-ackwards wrong.

Power meters don’t lie. Your brain, your heart rate, your speedometer, all lie like rugs. Worse yet, your poor brain (at least mine anyway) doesn’t know who to believe when all these guys start shoving conflicting data at it. Now I can tell them all to SHUT IT – I know what % of my FTP I’m riding. I know what % I SHOULD be riding. If I want to sit on 260 watts, that’s what I do. I don’t even look at speed or heart rate. Just those lovely watts.

Remember that PM’s tell you at any given time how hard you are working to move your bike against all those factors trying to slow it down: Aerodynamic drag (the big one), rolling resistance, gravity (if climbing). It FEELS the slight upward grade, head-cross wind, change in road surface, even if your brain doesn’t (it doesn’t but your muscles do). And since you know your FTP, you know HOW HARD YOU SHOULD RIDE. Not HOW FAST – HOW HARD. As a rough guide, you can average 70-75% of your FTP for an Ironman, and 80-85% for a 70.3. Spend a minute at 120% of your FTP, and say adios to a match. Only the redline gremlin knows how many matches you have to burn on a given day…

Back again to my DUMB riding. I used to hammer up hills, at 150% FTP, only to sit up and gasp for a while as I crested the hill while the gremlin (and his buddy Bonko the Clown) licked his chops. Now, I ride smarter, not any slower overall, but smarter. I just watch the PM, and yes I go slow in the middle steep section of a climb, but I go FAST over the top and down the other side, and no more leg smokage. In tests with non-PM sporting training partners, I typically watch them chug away in the middle of the climb, only to BLAST past them over the crest while they gasp for air. The PM has taught me how SLOW I need to ride sometimes, and how FAST I need to ride other times. You see, the COST (in matches burnt) of going just a TINY BIT faster on the steep is HUGE, and the benefit, in overall race time is TINY. The benefit of riding fast over the crest and setting yourself up for a very speedy descent is HUGE, and the cost is NIL. And yes I knew you were “supposed” to do this before I had a PM – but without seeing my power, I just didn’t know how to gauge my effort.

The first clue I had about just how dumb I ride was in Lake Placid 2007. I went too fast on the first loop, but I had been rendered EXTRA dumb by a computer bludgeoned senseless by the driving rain. With nothing but my perceived effort to rely on for this extremely hilly course, the gremlin was dancing on my quads long before the bike was over. But backing off is for wusses (I thought), so I kept pounding. At some point I realized I kept passing and then being re-passed by this one guy. This went on for many miles. Finally the guy said, “Sorry man – I’m not trying to yo-yo you – I’m just watching my power meter”. Yup – I WAS THE YO-YO. While he sat on a constant power output, I went too hard up hills and too slow over the top and down – the places where extra power = A LOT of extra speed. Eventually PM guy dropped me like a bad habit and Bonko and the gremlin danced a jig on my back. I won’t go into my meeting with the church ladies at the mile 19 aid station on the run.

So PMs are great for policing your effort in a race, and they are GREAT for training. You can do very precise interval sessions, riding for various times at specific percentages of your FTP in order to obtain specific training effects. Gauging interval workouts with heart rate and/or speed is just DUMB. Your heart takes too long to react, and it is only a weak indicator of how HARD you are going. Your heart is also worried about how much sleep you got, how hydrated you are, how many hours you trained last week and last month, that virus lurking in there, etc etc. Yes you should pay attention to how it reacts over time to various power level efforts, but don’t use it to SET your effort level. And speed or average speed is worse – there are just way too many variables affecting speed. I hear it all the time – my average speed was X and last week it was Y. So what? What was the net wind vector? What was your drag coefficient this week vs last week? How about your weight? TERRIBLY imprecise. But tell me your average power was x% better, and I’ll buy you a beer.

Like I said, you can MASSIVELY geek out with your power data. There is no better resource for this than Allen and Coggan’s book. It is also a good resource for basic PM usage -the propeller-head stuff is in the last few chapters.

Yup PM’s are EXPENSIVE. But no more so than race wheels, and often less. Let’s face it, triathlon is expensive, especially long course. And your time is valuable too – you won’t waste it training with a PM. You can get into one for <$1000. There are a few different types available, and the features and pro/cons is a subject for another article. But seriously consider getting one, and even better, get a coach to interpret your data and tell you how hard to ride and how to IMPROVE your power output. Because that my friends is where the rubber meets the road. All else equal, increase your FTP and you WILL be faster. Adios Bonko...