Kevin knows more than most about converting fitness to performance. Not only can he write about this topic, he has lived it, repeatedly.
I hope you enjoy this article.
When I guide clients toward their IM goals, I like to use Power, PE and HR. Used together, those three data points can give the clearest picture of real time efforts on the bike, cardiovascular stress on the body, fueling and hydration issues. As a coach who reviews power files of athletes seeking to race to potential, I often uncover key nuggets of data that are critical to unlocking the ability to execute a superior race plan; a plan that gives them the opportunity to run 26.2 miles _well_ off the bike. That race plan should include pre-race fueling (breakfast), correct swim, bike, run efforts and specific, individual hydration and fueling strategies. This is a good time to pause and say that not everybody needs a power meter to race well. Some athletes crack the code without using power or monitoring HR. If you feel you are one of those guys or gals, rock on!
If you find yourself under performing at your AAA race, listen up, it doesn’t have to be that way. Not many athletes nail their first IM. When it happens you’ll find somebody who did more than get fit; they also studied. Interestingly, many in this fraternity struggle in subsequent IMs. Given the fact that nearly everyone shows up to IM fit, and that much of the field underperforms relative to training markers, we can assume that important questions that focus on race execution are going unanswered or ignored. Our personal 'best races' will happen when we feel no fear and have the confidence that we are well prepared. Having race ‘experience’ implies that we have had the opportunity to answer questions that relate to execution. What type of experience you bring to the table is dependant on whether you learn from your success and/or failure. It is imperative that an athlete be honest with self about past performance and racing/training efforts; identifying what needs to happen to catapult to the next level. Beyond fitness, what needs to happen? (1) often it is finding the focus to complete and execute your race plan within specific efforts levels more than a specific time goal. (2) I think it wise to begin by focusing on personal excellence; which results in your fastest finish time. (3) for many athletes struggling to get it right, training and race experiences highlight this truth – there is a need to reduce efforts over the early part of the race. (4) many athletes fail to understand that to perform, we need to structure our preparation so that IM becomes routine as possible. With those thoughts in mind, I have some suggestions.
IM requires that we have a plan. Then, you need the ability to discern whether the plan was executed effectively. Often, athletes use ‘end of race’ power averages as a way to help answer that question. Good stuff, because a well executed IM bike will show quite specific power averages. However, averages don’t readily acknowledge tactical errors, power spikes, fading watts, rising HRs and declining power. Averages may hide events that render a plan obsolete. You can have great looking ‘entire ride’ averages and blow yourself to bits. Those who study successfully executed IMs will tell you that vast majority of the races they examine have _very_ similar characteristics. In fact, many of us believe that even those athletes that do not use a power meter would produce power files similar to successful athletes who do ride with meters. In other words, while it is not necessary to ride with a power meter to execute well, using one can benefit athletes that struggle while relying on PE and HR.
What should entire ride averages look like? I have heard some suggest that the range for correct power over a flat IM bike might be from an average of 65% of FTP for the less fit, to above 75% of FTP for the very fit (Functional Threshold Power being defined by Andrew Coggan as a well executed, best effort, avg power over a 60min TT). In my practice, I have found a smaller range signals success // more like 70-73% FTP. Averages in the 74-75% range may be successfully used by the very fittest athletes riding 4:30 and running sub3 marathons because their race day is abbreviated relative to most of the field. Even for the elite of the elite, riding above avg 75% FTP for an IM ride while hoping to have a lifetime best run attached appears optimistic. If it has worked that way for you, and you are riding 5-6hr bike splits you might consider that identified FTP was low // or that you may still have a better run in you over 26.2 miles off the bike. Very few athletes will purposely choose to ride harder, knowing they are hurting their run, hoping that it upsets their competition’s race plan in a significant way.
An important point -- I think very wide ranges of % FTP used in IM (correctly or incorrectly) are associated with a foggy notion of what FTP really was to begin with (high or low) prior to race, and those foggy numbers become even less clear when early pacing errors and poor fueling tactics begin to skew data beyond usability. As we move away from relative elite fitness or the very strong AGer, we generally move toward the less experienced athlete. The less experienced athlete is typically less able to identify FTP in a way that accurately translates to a 5.5 to 6.5 hour ride + fueling + successful marathon. However, in my experience, if/when the less experienced, moderately fit athlete does ID correct power ranges, either alone or with an advisor, the average percentage of FTP used over an IM is still in the 70% range, as long as they find a real FTP number.
Again and again and I see athletes over estimating FTP through a 20min test, or by sitting up the last 5min to boost numbers or by focusing too much of training on swelling threshold power numbers without confirming execution of correct IM efforts over 5-6hrs of biking as it fits into 9-12hrs of racing. Not only do I think a 20min TT is too short as a test, it doesn't seem to translate well to a 5-6 hour ride. I have found the 30min best effort TT (-5%) to be a relatively good proxy for the 60min test. Still, the 60min TT is better, and past successful HIM and IM performance with excellent runs attached the best.
An athlete’s threshold and correct IM power ranges are initially located through the relatively short but tough test mentioned above and then can be tracked over time. The second, more difficult and confirming test (say, race simulation ride or a Big Day Brick) is used more sparingly over the last 10-12 weeks in specific prep, prior to your AAA race. It is a reality check. The best predictors of IM performance are the KEY workouts in specific prep and the library an athlete builds of past IM performances; the races with good runs attached // not the 30-60min TT for threshold power. The short tests are quit helpful, but not enough. Athletes who depend on short test FTP numbers alone, often use about 5-10w too much over the first half of the course; just enough to cause digestive disturbance, significant dehydration and a sub-optimal run.
CyclePeaks gives your power file a Variability Index: VI is normalized power divided by average power. Does a tight VI mean you raced optimally? If an athlete incorrectly names his/her race efforts via power, a tight VI does not represent optimal race execution, only good execution of a faulty plan. Further, because an athlete's optimal plan should show quite a bit of variable power on courses with terrain changes, an overview of execution should include the athlete's approach to flats, rollers, extended climbs and descents. Correctly identifying the %FTP to be used over variable terrain and riding tactically will result in a tight VI. In my experience, VI has less to do with the actual power used and everything to do with how the power is applied. A larger VI reflects power spikes (the way power is applied or removed suddenly // it is tactical). Tactics in IM, where we successfully run a marathon off the bike, are different that those used in bike only races.
Over the course of an IM, an athlete can shift from seconds of threshold watts (100% of FTP) while cresting a climb, to moderately hard power used on extended climbs (80-86% FTP) to steady flat efforts (70-73% FTP) to soft pedaling descents (say 50-65% FTP or less) and still ride with a tight VI. In fact, if done correctly, averages will fall in that 70-73% range. It is the transition from one power to the next that can damage your ability to run well. Your strongest race via power will have a tight VI if you obey power caps and shift efforts purposefully. Power spikes are what make VI large. Example: at IM Hawaii, a ride with steady efforts on flats, moderately hard efforts on rollers and extended climbs, seconds of well placed threshold efforts and soft pedaling the descents, will give a VI near 1.04 if shifting efforts is done carefully. I think anything over 1.05 for IM is failure to execute optimally with regards to running your best for 26.2 off the bike.
My must do’s prior and during an IM Race == >
1) correctly identify FTP with 95% of 30min TT power (minimum) or 60min TT for some. Use these numbers in conjunction with PE and HR and *note if and when power can be tactically misleading (heat, dehydration, calories intake, etc).
2) corroborate findings above as correct IM efforts over 5-6hr race simulation ride // or better yet, as part of Big Day Brick where ride and run-off follows race breakfast and tough 4-5k swim (very helpful).
3) in specific prep, marry results from #1 and #2 with correct HR caps, experienced PE and proper fueling
4) use varied power that fits specific parts of the course (climbs, rollers, flats, descents). Use established threshold and VO2 watts as max caps to be used rarely or numbers never to be seen.
5) *apply variable power changes while avoiding power spikes* (resulting in VI at or below 1.05)
6) fuel the bike as part of your determination of race execution – they are intimately connected. If you cannot eat and stay aero at a given effort, and then run well, you better seriously consider a new bike position and/or your named FTP. Give yourself a chance to run to potential!
*For best pre-race preparation I'd like to see a greater emphasis placed on field tested FTP (not indoors) melded with well executed long race simulation workouts (breakfast, swim, bike + run-off.
In addition to Power, I pay close attention to HR guidelines as heart rate is an objective measure of cardiovascular strain. You might have a very accurate idea of threshold power and power guidelines for your IM, but if you don’t fuel and hydrate well, your performance will suffer early, perhaps even ending your race should you fail to slow down and correct the errors to that point. In IM, I strongly suggest you monitor heart rate over riding by power alone. Beware of thinking those numbers are redundant; the two markers tell different tales. I always track Power, HR and PE. In problem situations, if things get funny (as they sometimes do) I may have to go with PE, lower HRs and alter my plan until my body returns to a recognizable working order. Ironman is a long day. Acceptance can be difficult. One of the great lessons of IM is found in the frustration that comes from poorly executed races. They force the athlete who is listening to accept reality. There is always a reason things go right – and there is always a reason things deteriorate. We all know someone who at times can race very well on PE alone. If that isn’t you, hang in there; it’s possible for everyone to figure this IM puzzle out.