Exercise scientists have two basic ways of measuring performance in their studies. One is a time trial, where subjects are asked to cover a specified distance in as little time as possible (or cover as much distance as possible in a specified amount of time). The other is a time to exhaustion test, where subjects are required to sustain a fixed work rate (speed or power output) as long as possible.

In the real world, most runners approach most marathons as time trials. In my coaching role, I generally advise runners to take this approach because it offers the best odds of a satisfying outcome. The idea is to choose a time/pace goal that is challenging but realistic, start the race at this pace, and then make adjustments along the way based on how you’re feeling. The advantage of this strategy is that it limits the risk of hitting the wall. When a runner is even slightly too aggressive in the early part of a marathon, he is likely to slow down precipitously in the later part and consequently fall not seconds but minutes short of finishing the race in the least time possible—if he finishes at all. To avoid “wasting” a marathon (not to mention the months of preparation leading up to it), a runner must be a little conservative, choosing a target pace that he’s very confident of being able to sustain for the full distance and relying on a fast finish to avoid leaving time on the table if it turns out that the target pace is a tad tooconservative.

This fall, Eliud Kipchoge will make a second attempt to break the hallowed two-hour marathon barrier. He got very close in his first attempt, covering 26 miles, 385 yards in a time of 2:00:25 in Italy in 2017. Of necessity, Kipchoge approached this bid to make history not as a time trial but as a time to exhaustion test. Aided by a phalanx of pacers, he set out at 4:34.5 per mile (1:59:59 pace) and held on as long as he could, which turned out to be about 18 miles, at which point he began to slow involuntarily, despite his best efforts to hold the required tempo.

In his second sub-two bid, which will take place in late September or early October, Kipchoge will take the same approach, as indeed he must, for such an ambitious goal cannot be achieved in any other way. Avoiding the wall is not a concern, because anything short of sub-two is failure. Whether Kipchoge hangs on almost all the way and ends up clocking an excruciating 2:00:01 or blows up at 35K and literally crawls to the finish line, the two-hour barrier will remain in the realm of the impossible for the time being. Thus it makes no sense for Kipchoge to adjust his pace as he goes based on how he feels. If 1:59:59 (or better) is indeed possible for him, he will only get there by forcing himself to hold that 4:34.5/mile pace no matter what.

My (possibly politically incorrect) term for a marathon that is run as a time to exhaustion test is kamikaze marathon. Inspired by Eliud Kipchoge, I have decided to run a kamikaze marathon of my own this fall. A sub-two-hour marathon being slightly out of my reach, I will attempt to sustain a pace of 6:04 per mile as long as I can in the context of the Pacific Northwest Marathon on September 21. The fastest pace I’ve ever sustained for the full marathon distance is 6:05 per mile, at the 2017 Chicago Marathon. I was 46 years old then and am 48 now, a difference that is far more consequential as it relates to performance decline than is, say, the difference between 36 and 38. What’s more, I spent the summer of 2017 living in Flagstaff and training with Northern Arizona Elite, a huge advantage that I will be lacking this time around. In consideration of these facts, I think I’ve got about as much chance of achieving my goal as Kipchoge has of achieving his, which is to say close to none. But that’s the whole point of a kamikaze marathon. You choose a goal time that you think is probably-not-definitely impossible for you and go for it! If you plan and execute appropriately, there’s about a 90 percent chance you will implode painfully in the late miles of your chosen race and a 10 percent chance, give or take, that you’ll achieve something special that you would not have been able to achieve with the usual time-trial approach.

So, what do you say—are you in? Before you blurt, “Hell, yeah!”, understand that Kamikaze marathons are appropriate only for seasoned marathoners who don’t mind possibly “wasting” a marathon. But if you fit this description, do consider joining Eliud Kipchoge and me in running a kamikaze marathon this fall. Put some thought into coming up with a time/pace that is probably-not-definitely impossible for you and then find an appropriate event. (I chose Pacific Northwest because the course is net downhill and mostly flat and the weather is reliably perfect every year—oh, and because my brother Josh is running it). Also consider recruiting a pacer who can easily run the time you’re hoping to run. Tommy Rivers Puzey, a 2:16 marathoner, has agreed to serve as my pacer (though there’s a chance he’ll have to bail out at the last minute due to sponsor obligations).

If you accept the kamikaze marathon challenge—and I hope you do—be sure to share the journey (Strava, Twitter, etc.) as I will be doing in the months ahead. Let’s make this a thing!