The Value of Power for the Triathlete

150 150 Rich Strauss
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Use a powermeter to build a bigger engine, and more power, on the bike!

With three sports to train and race, triathletes are assaulted from three directions with the question “where should I invest my limited time and money to achieve the best return on race day?” We feel that a powermeter is an excellent investment for the triathlete to make in their training and racing, when compared to similarly priced investments.

A powermeter is a crank or hub-based device which directly measures the work, called a “watt,” performed by the cyclist. It’s this “direct measurement” piece that creates the value, and power, of a powermeter for triathlon training and racing. But before we discuss the value of power for the triathlete, let’s first discuss how power relates to changes in fitness…and don’t forget to signup at the end of this article for a FREE download of our 8 Week Bike Focus training plan!

Improved fitness is the ability to perform more work

In January you perform a time trial and ride your bike at 19mph for 10 miles. You then train and train, retest yourself in May, and are able to ride your bike at 21mph on the same 10 mile course. You’ve gotten faster…or have you? Speed can be significantly effected by wind so it can often be difficult to make comparisons from ride to ride due to changes in wind conditions, even on the same course. A powermeter, however, provides an objective measurement of the work performed for each ride. So lets assume that in January you averaged 200 watts for your time trial and in May you averaged 230 watts. From this we can absolutely say that you performed more work in your May test.

Improved fitness is then the ability to perform more work, the functional expression of which is more power produced by the rider. More power, all others variables held constant, will result in higher speed on the bike.

Time Efficient, Targeted Training

If the functional expression of improved fitness is the ability to perform more work, then a powermeter, as a tool that directly measures the work performed, affords us the opportunity to make our cycling training more targeted and time efficient. The analogy we’ve found most useful is weight lifting, as most athletes have dabbled in strength training at some point.

Let’s say your goal is to improve your bench press:

  • You do a test to determine how much weight you can lift one time, your One Rep Max Bench press, and test at 175lb.
  • Then, during your lifting sessions each week, you put weight on the bar as fraction of this 175lb and lift it. For example, 3 x 10 at 150lb the first week, then 3 x 12 at 150lb the second week, then 3 x 10 at 160lb, etc.
  • Each week, by increasing the weight and/or reps bit by bit, your body performs more work, forcing it to adapt to meet this higher and higher work requirement, the functional expression of which…
  • You test in Week 8 when your One Rep Max increases from 175lb to 195lb — you’ve become more fit, the functional expression of which is the ability to lift more weight, to perform more work.

Power training on the bike follows a very similar process:

  • Perform initial testing to determine the watts you can hold for a sixty minute time trial. We call this your Functional Threshold Power (FTP).
  • You then perform interval training, as repetitions at some fraction of your FTP.
  • Each week the length of each interval, and the sum of these intervals, is dialed up a bit, forcing your body to perform more and more work and adapting to meet this higher work requirement.
  • Interval training and targeted wattages are also applied to your longer endurance rides.
  • Test again, establish a new FTP and associated training zones, and start the cycle over again: later, rinse, repeat.

What’s important to realize in both examples is that:

  • We have an objective benchmark with which to measure beginning fitness. We know exactly what we can do.
  • Training is metered according to this benchmark: we always know what we should be doing each day, as a percentage of our demonstrated “can do” number.
  • Improvements in fitness are captured through periodic testing, which sets new benchmarks and training wattage zones…raising the bar again.
  • Throughout this process there is no wasted time or ambiguity — all I have to do is look down at the powermeter to see an objective number on the dial that tells me what I’m doing now in relation to my demonstrated fitness and my workout goals for the session. There is no hiding, in other words, and every minute of training time invested is applied to my fitness goals very efficiently.

Fewer Pacing Mistakes on Race Day

But racing is where the powermeter becomes most valuable for the triathlete, especially in half and full Ironman® distance events: the longer the event the more success is a function of simply not making mistakes. In an Ironman, for example, large or small mistakes made over 112 miles of cycling now have a marathon, 26.2 miles, to express themselves!

The knowledgeable power triathlete knows exactly the optimum work rate and total work she can perform during the bike leg and still run well off the bike.  And she always knows, in real time, exactly how much work she is performing relative to these numbers.

The non-power athlete lacks this level of granular, real-time, objectively measured data. Instead, he must rely on the subjective feedback of heart rate and/or rate of perceived exertion (RPE). In fact, the heart’s response to increased power is delayed by about 90 seconds and so small, or even very large, pacing errors can be difficult to capture through heart rate alone. And RPE can be skewed by the excitement of the race, the feedback received from athletes around us (“I guess I’m supposed to hammer up this hill because everyone else sure is…), etc.

The net is that the knowledgeable, disciplined power athlete simply makes fewer pacing mistakes on the bike and is more likely to set up the run than the non-power athlete. In our experience (coaching over 1000 Ironman® finishers each year since 2010), the Ironman® run course is littered with the bodies of very, very fit athletes who made pacing mistakes on the bike. A powermeter then is in many ways a stupidometer, a tool that tells when you’re being stupid, so you can stop being stupid ,and not join your friends in very, very long walk on the Ironman® run course.

In summary, a powermeter is an excellent investment for the triathlete to make in their training and racing, especially when compared against similarly priced options:

  • As a direct measure of the objective of improved fitness — higher work output — a powermeter facilitates extremely effective and time efficient training.
  • When correctly applied on race day as a race execution tool, a powermeter enables the triathlete to make fewer pacing mistakes on the bike, setting up the run. This “stupidometer” effect is more pronounced in long course triathlon, where execution skills trump fitness.





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