Think about the last race you completed. Could you have gone any faster than you did? It’s a very simple question, yet a difficult one to answer in many cases. If you committed a major error in execution, such as running an entire track race in lane three, then it’s easy to answer in the affirmative. But if you did manage to avoid obvious mistakes, it’s hard to know whether or not you might have been able to squeeze out a few more seconds. In fact, it’s impossible to know.

Why? Because an unimprovable race performance requires perfect pacing, and perfect pacing is impossible to define or measure. Pacing entails purposely holding oneself back from one’s physical limit, and it’s this gap between self-imposed limit and physical limit that makes perfect pacing undefinable and unquantifiable. A true maximal effort cannot be sustained longer than 30 seconds, give or take, so athletes aim to sustain a level of effort that will put them at their physical limit when they’re within 30 seconds of the finish line and fatigue has reduced their capacity to match the level of their chosen effort. But no athlete ever sustains a perfectly steady output in a race and it’s doubtful that a perfectly steady output is even optimal. In long races, it’s not uncommon for an athlete to go through one or more rough patches, when their perceived effort level spikes, and most experts would agree that reducing one’s effort level slightly at these times leads to a better final outcome. Furthermore, research on pacing in real-world environments suggests that the best outcomes occur when athletes are able to kick (i.e., accelerate) at the very end of the race, which indicates they could have gone faster prior to that point—a paradoxical phenomenon, as it essentially means that athletes go fastest overall when they could have gone faster prior to the homestretch. Further muddying the waters is the fact that athletes’ performance limits are mutable, varying from one circumstance to the next based on a myriad of factors affecting perception of effort. For example, athletes almost always go faster in a group than they do alone.

Despite all this complexity, we have a pretty good idea what a perfectly paced race looks like as a platonic abstraction. A graph of such a performance would consist of two lines, one flat and the other upward-sloping. The flat line represents the athlete’s output (power, rate of energy expenditure), which remains quite steady between the start and finish. The upward-sloping vector represents the athletes’ perceived effort, which rises with perfect linearity over time and peaks just as the athlete finishes. These two lines indicate that the athlete has parceled their energy efficiently throughout the race and finished with nothing left in reserve. But again, this is an abstraction, and in any given real-world case it’s impossible to know if the athlete truly paced their race perfectly.

Putting aside the unknowable nature of perfect pacing, most runners fall far short of perfection in their race pacing. This isn’t just my opinion—studies prove it. That’s why I wrote On Pace: Discover How to Run Every Race At Your Real Limit. Do you need this book? Let’s find out. To test your current pacing ability, try the following test: First, determine your average pace per mile or per kilometer in your last half marathon. Next, go for a run. After warming up, run one mile or one kilometer at half-marathon effort, aiming to nail your exact average pace from your last half-marathon without looking at your watch. Note your actual time, then send your results to me here: matt@8020endurance.com by September 10th, 2022.

The 80/20 Endurance Pacing Challenge will operate on the honor system, so I’m trusting you not to lie or cheat. But you have little incentive do so, as no prizes will be awarded. Instead I will compile the results and share them in a future blog post, in which I will also provide tips on getting better at pacing.

Note that being able to hit a target pace accurately is not quite the same skill as being able to complete a race in the least time possible. But they’re similar enough that runners who are good at either one are almost always good at the other. Hence, if you run test mile or kilometer more than a few seconds too fast or slow, you have cause to believe you’re not pacing your races optimally and will benefit from reading and applying the methods taught in On Pace. If you prefer to skip the test and go straight to the book, you can purchase it here. And if you’re on the fence, you can read a free sample chapter here.