The past three weeks, I have been in stealth mode, ramping my training back up in a three week push to get race ready. October 10th, I swam 2.4 miles and biked 80 miles at race pace. Then limped along to 32 miles more on the bike and shuffled for 10 miles. I had no idea what this might do to my ability to do serious Ironman training all over again for a race six weeks later, on November 22nd. What I discovered was that I had full capacity for swimming and running within 5 days. Biking, I let a week go by before trying any real hard or big stuff, but by the second week, I’d done a 40 minute time trial and a 100 mile ride in under 6 hours.
My body seemed fine, but my confidence had taken a serious hit. I have never done an Ironman yet when I felt that my biking was strong enough. Swimming, I’m always ready for. Running, as long as I pace the bike properly for my level of training, I can crank out an awesome race and finish strong. It’s my bike that often disappoints me.
There is a solution to this, and it costs $1,000. Buy a power meter. I have been studying in depth the past two months how power can guide training, and also a race. I haven’t bought one yet for two reasons: I already have one, and I don’t want to break one of the Prime Directives.
One of the fundamental truths handed down in Ironman lore is: don’t change anything close to or during the race. This applies to all sorts of things: don’t buy a new bike a month before the race. Don’t get re-fitted on the bike you already own. Don’t fiddle with the training plan in the last nine weeks or so before a race. Don’t use a wet suit you’ve never tried before, or a saddle, or shoes, or nutrition. Go with the tried and true, even if it seems a little out of date or may be ineffective. Wait until after the season is over before you go fiddling with your equipment.
Especially after I violated another one of the Prime Directives in Kona – go EASY in the first thirty miles of the bike – I have a great fear of breaking any of the Rules I know are valid. And this is one of them.
So I will go with the “power meter” I already have. Which is an iBike, and which is quite finicky, and suspect in its consistency and therefore reliability.
A brief tangent about “power”, for those unfamiliar with the term as applied to cycling. Start with the idea that I’m racing – trying to go as fast as I can. But I have a very specific journey: first swim for about 70 minutes, then bike 112 miles, and then run a marathon. There should be a formula for how much energy I can expend swimming and biking to have enough remaining for a competitive run. There should be a formula, or a prescription, but the variables are so great, and the day is so long, that it is almost impossible to get it perfect. One is either too tired or too fresh for the run. But how do you get as close as possible to the sweet spot?
There are five measurements one can make while biking that might help: speed, time, heart rate, perceived effort level, and power generated. Assuming you know what the first three are and how they are measured, I’ll talk about the last two. Perceived effort is the internal sense of how hard one is working. It’s a sense that must be developed and refined through repetition. The problem with it is that all of the learning opportunities, except an actual Ironman race itself, come at a time when one is either more tired, or less well trained than one will be at the start of the bike portion of the race. In short, there is a tendency to work harder than one should, because one is both well-trained, and well-rested. So what should seem hard seems easy, especially at the start.
The same problem exists with speed, time, and heart rate. Things learned while training about what’s possible and sustainable are difficult to use during the race, not only because of that well-trained and well-rested state, but also because one NEVER runs a marathon after racing 112 miles on the *except* when racing. If you tried that, you’d never get any training done, because you’d need to rest for a couple of weeks after the effort, and thus lose 14 days worth of training to improve yourself.
But POWER – that is the holy grail here. Power is a measure of the force being applied to the bike to generate forward movement. The ability to generate power is independent of the forces one is working against. Wind, hill gradient, weight of bike and rider – all of these will vary from day to day, and from minute to minute within the day. But 180 watts of effort is ALWAYS 180 watts of effort, in a way that 20 mph is NOT always 20 mph – imagine how easy it is to go 20 down a hill, and then try to go that same speed back up the hill.
In the past ten years, cyclists, exercise physiologists, coaches, and engineers have learned how to use the information about watts generated while biking to improve both training and racing. To describe how that works would take a book, and I’m not about to try here. Suffice it to say that with a power meter, one can systematically train to improve the ability to ride 112 miles in a race, and one can also use information gained while training with power to control the effort level during that race, in a way which ensures sufficient energy left to run well. So I should really have a power meter.
What I have is a gizmo that uses a wind sensor, an accelerometer, a tiltometer, a barometer, a speedometer, a thermometer, and a nifty software algorithm to determine the forces I am working against. To those forces, the program adds other information, such as my total bike/rider weight, my position on the bike, how fast I can coast up a given hill gradient, to calculate how much power I am generating. It actually works very well, when things are stable.
BUT – it doesn’t work so well unless everything is perfect. Temperature below about 55F? Fuzzy data. Bumpy road? Accelerometer rattles too much. I move my hands near the wind sensor? Calculated power may go down.
It’s a great idea, and actually well-executed and supported. But it is just not reliable enough to always use during a race. When it works, it’s great. But it may at a moment’s notice start spitting out patently false data, such as telling me the slope I am climbing just went from 6% to 92%, and thus my watts went from 212 to 4000. How useful is that when I am trying to keep my watts below 200 up the climb.
But it’s what I’ll go with on race day in Tempe, this year. It has heart rate data, it has speed, it has cadence, and all those are helpful to me if the rest of its gizmos go on the fritz. But for next year, I will get a new source of data. That will be another story when I do make the decision to buy, as there are several options, each with its pluses and minuses.
Oh, and I also intend to get a professional bike fitting in December, after the race. Because, as Chicago Cubs fans learned so many years ago, there’s always next year.