A historical perspective on why weekly mileage and monster long runs still dominate the conversation despite advances in training science.
In any ultrarunning group, the same questions come up again and again:
How many miles per week should I run for a 100K?
How long should my longest run be for a 100-miler?
These are reasonable questions. Mileage matters and long runs matter.
But are these still the right questions to ask?
Let’s explore why chasing mileage goals has become so deeply ingrained in ultrarunning culture. The answer may lie in the sport’s evolution.
Ultrarunning Grew Up on Mileage
For much of ultrarunning’s early history, training was largely organized around mileage: weekly mileage, the length of the long run, and gradually running farther. No surprise there. If you want to run for hours on end, you’d better practice running long.
Early ultrarunners entered largely unexplored territory, and many came from marathon and road-running backgrounds, where weekly mileage and progressively longer long runs were central features of training. Ultrarunning inherited much of this framework and, quite logically at the time, extended it: if preparing for 26 miles required substantial mileage and long runs, preparing for 50 or 100 miles surely required even more.
In the early days, no large body of ultramarathon-specific science told athletes how to prepare optimally for mountainous events lasting 10, 20, 30, or more hours. Training was based largely on experience, trial and error, and what had worked for others.
This mileage-centered way of thinking persisted for decades. Even well into the 2010s, it remained a dominant way of structuring ultra training. Plans often included hills, recovery, fueling, strength, and other useful elements, but mileage remained the dominant organizing framework.
That helps explain why questions like “How many miles per week?” and “How long does my longest run need to be?” remain so deeply embedded in ultrarunning culture.
The Pioneers Weren’t Doing It Wrong
None of this means that early ultrarunners trained badly. Quite the opposite.
That approach produced extraordinary athletes and extraordinary performances. Experienced runners certainly understood that mountains required training in mountains, that downhills trashed your legs, that you needed to learn to eat while running, and that spending a long time on your feet mattered.
What athletes and coaches generally lacked was the systematic physiological framework we use today to think about race demands, durabilityDurability refers to the time course and magnitude of deterioration in an athlete’s physiological, mechanical, and performance-related characteristics… More, eccentric loading, recovery capacity, training-load distribution, and how different types of training contribute to performance. Our understanding of endurance nutrition and race fueling has advanced along with the training approach.
The ultra pioneers were training according to what was known and accepted at the time. It was best practice then.
But best practice evolves.
Just Look at Western States
Western States offers a striking illustration of how much the sport has evolved. (see footnote)
In 1994, Ann Trason ran 17:37:51, breaking her own women’s course record by nearly 40 minutes and finishing second overall. Ten years later, Scott Jurek won in 15:36:27, during his remarkable run of seven consecutive victories.
Fast-forward to 2026.
Vincent Bouillard ran 13:46:15, becoming the first runner to complete the modern Western States course in under 14 hours. Ten men finished faster than Jurek’s 2004 winning time.
Jennifer “Jen” Lichter, making her 100-mile debut, won the women’s race in 15:28:05, breaking Courtney Dauwalter’s course record—and running about eight minutes faster than Jurek’s winning time in 2004.
Alongside more structured training approaches, today’s athletes benefit from better fueling, equipment and footwear, greater professionalism, deeper competition, and decades of accumulated knowledge. So we cannot attribute the improvement in finishing times to modern training alone.
But the larger point is clear: ultrarunning has evolved enormously, and training methodology has evolved with it.
What represented best practice 20 or 30 years ago does not automatically represent best practice today.
From Mileage to Race Demands
Because mileage has historically been such an important way to organize ultramarathon training, many runners still use it as a proxy for readiness today.
“I’m running 80 miles per week.”
“My longest run was 45 kilometers.”
Those numbers tell us how far someone ran. But they leave out much of what determines the actual training stimulus.
Two athletes can each run 80 km per week while doing very different training. One may run mostly flat roads; the other may run technical mountain trails with substantial climbing and descending. The distance is identical, but the recovery needs and physical adaptations can differ substantially.
That is where the modern physiological framework becomes useful. Simply chasing mileage often overlooks important race-specific qualities such as musculoskeletal durabilityDurability refers to the time course and magnitude of deterioration in an athlete’s physiological, mechanical, and performance-related characteristics… More, climbing capacity, and tolerance to the eccentric loading of repeated descents—qualities that flat mileage alone cannot adequately develop.
Instead of starting with:
How many miles should I run?
Start with:
What are the demands of the race, and what training does this athlete need to meet them?
A mountainous 100K or 100-mile race requires much more than simply covering a lot of miles. How much climbing and descending is involved? How technical is the terrain? How much power hiking will be required? What demands will the race place on durabilityDurability refers to the time course and magnitude of deterioration in an athlete’s physiological, mechanical, and performance-related characteristics… More, downhill conditioning, fueling, and the ability to perform in heat or altitude?
And perhaps most importantly:
Which of those qualities does this athlete already possess, and which need to be developed?
Now we are no longer simply prescribing miles. We are preparing an athlete for a particular race.
That preparation may include substantial mileage and long runs, but also climbing, descending, power hiking, strength training, downhill conditioning, back-to-back sessions, multi-day training camps, heat acclimation, fueling practice, and appropriate recovery.
The goal is not simply to accumulate more miles. It is to accumulate the right training, in a form the athlete can recover from, adapt to, and consistently build upon.
The best long run is not necessarily the longest one you can survive. It is the one that provides a useful training stimulus without exceeding your recovery capacity or compromising the training that follows.
Where The Old-School Thinking Becomes a Problem
Mileage itself is not old-school. Neither are long runs. Both remain important parts of ultramarathon training.
What I consider old-school thinking is believing that every runner needs to reach a particular weekly mileage—or that someone must complete a prescribed monster long run to succeed in a 100K or 100-mile race.
Training success does not come from ticking off one heroic workout or hitting an arbitrary weekly mileage target. It comes from accumulating appropriate training over time.
The best long run is not necessarily the longest one you can survive. It is the one that provides a useful training stimulus without exceeding your recovery capacity or compromising the training that follows. Your long runs need to fit into and complement the rest of your training.
So stop letting mileage drive the plan. Focus more on time on feet, race-specific terrain, and your race’s training demands. Let the mileage be a result of the training rather than the target.
That mindset is very different from simply chasing miles.
The Takeaway
Mileage still has a place. But it should be one piece of the training picture—not the picture itself.
The pioneers of ultrarunning pushed the boundaries of what people thought was possible and built the sport we enjoy today. We should respect what they accomplished while recognizing that both the sport and our understanding of how to train for it have evolved.
Best practice evolves. Your approach should evolve accordingly.
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Cover image by the author, based on a photo by Alin Serban on Pexels.
Footnote
Western States course configurations have varied over the years, so historical finishing times aren’t perfectly comparable. Scott Jurek’s 2004 win was on the “Star Fire” course used from 2002–2005, which Western States considers the fastest main post-1986 course configuration. The current “Miller’s Defeat” course is considered the slowest, with Western States estimating the difference between the two at roughly 10–20 minutes, depending on the runner. The 2026 race, meanwhile, was exceptionally favorable for fast times, with very cool conditions and one of the deepest competitive fields in race history. The comparison therefore illustrates the sport’s broader progression rather than providing a tightly controlled measure of performance improvement. — back up ↩