In my experience, most ultramarathon athletes, even the elites, find success through a lack of failure on race day. They achieve their goals, win races, and get those coveted belt buckles not because they ran one section very well but because they prevented the negative. They prevented time spent at 0 miles per hour. They prevented themselves from becoming a nauseous, sore, blistered, battered, and stumbling mess. They continued to be able to eat, drink, and locomote down the trail, even if it was not very fast.
Because so many things can go wrong, and the penalties for failure are high, “success by lack of failure” is a key element in successful ultramarathon running. These failure points are somewhat universal, as indicated by the research I cover further in my book Training Essentials for Ultrarunning, and help define the limiting factors for ultrarunning. The very small exception is elite athletes competing in 50Ks and 50-mile distances and flat 100Ks. This is because the finish line for the elite athletes in those races often comes before the failure points have a chance to impact performance.
All reasonably healthy individuals can locomote at the necessary speed to beat the cutoffs for any ultramarathon. I say this not as an opinion but as a biomechanical fact. The preferred walking speed for the average human is around a 19-minute mile (Levine and Norenzayan 1999; Browning and Kram 2005; Mohler et al. 2007). With a little effort, one can easily achieve 18-minute miles, which is a pace that would yield a 30-hour 100-mile finish.
As of this writing, Timothy Olson holds the course record for the Western States 100 at 14:46:44. This time works out to about 8:50/mile. When we tested Timothy in our lab, his lactate threshold pace was under 6:00/mile. At a pace slower than 6:00/mile, his aerobic system can keep up with his energy demand, delivering oxygen to his muscles at a rate that is sustainable with few negative byproducts.
Having coached Timothy since he set that record, I can attest that on any given day, an 8:50/mile pace is not challenging for his cardiovascular system, even on terrain similar to that of Western States. Yet if you look at his Cal Street section (from mile 62 to mile 78), you will see that he ran for 16 miles with a net elevation loss at a pace of nearly 9:00/mile. From the standpoint of cardiovascular fitness, that 9:00/mile pace, which is more than 50 percent slower than his lactate threshold pace, was easy. It was essentially a normal recovery-run pace for him.
So why, on race day, 62 miles into a record-setting performance, couldn’t Timothy run faster than his normal recovery-run pace? The answer lies in the fact that there are many stressors on race day, and success in an ultramarathon has far more to do with your ability to cope with the sum total of those stressors than with just the capacity of your cardiovascular system.
How you handle those other stressors determines whether you succeed due to lack of failure.