⏵ Course guide · South Dakota hill-repeat ultra
TutHell 50K sends its field up the same short hill at Tuthill Park in Sioux Falls, South Dakota, one hundred times, a format the race itself brands as the city's most brutal ultramarathon. I will walk you through the loop and the repetition first, then give you a pacing and fueling plan built for a hundred-loop hill-repeat day. There are free calculators along the way to dial in your own numbers.
These facts come from the official TutHell 50K site. Much of the site loads dynamically, so entry details and the current cutoff are best confirmed directly there before you commit. Race logistics change year to year.
There is no varied terrain to describe here, and that is the entire point. TutHell runs the same roughly third-of-a-mile loop at Tuthill Park a hundred times, each one climbing about 90 feet, for a total somewhere around 9,000 feet of gain by the finish.
Where most 50Ks vary the terrain to keep your mind engaged, TutHell strips that away entirely. You will see the same hill, the same footing, and the same short climb a hundred separate times. That repetition is a genuinely different mental challenge than a varied trail course, and it is exactly what earns the race its self-declared title as Sioux Falls’ most brutal ultramarathon.
At roughly a third of a mile per loop, you pass your own drop point or aid setup extremely often, likely more than once every five minutes at a steady pace. Use that access: stage exactly what you need for the next handful of loops rather than carrying a full race's worth of gear, and treat every pass as a chance to check in on your fueling and your feet.
Pacing a hundred identical loops is less about hitting splits and more about finding a rhythm you can hold without your mind or your legs breaking down from the sheer repetition.
A grade-adjusted pace target for the roughly 90 feet of gain per loop gives you an honest sense of a sustainable climbing effort. Because you repeat it a hundred times, small pacing mistakes compound fast, so settle into a rhythm within the first several loops and resist the urge to push simply because an early loop felt easy.
A hundred loops is a hard number to hold in your head all at once. Use a race-time prediction to estimate your overall pace, then break the day into blocks of 10 or 20 loops with their own small mental checkpoints, so "one hundred loops" never has to feel like one overwhelming task.
⏵ Free tools to pace this course
With a loop this short, fueling logistics are simpler than almost any other ultra format, you are never more than a few minutes from your own gear.
Aim for roughly 60 to 90 grams of carbohydrate per hour and sodium in the 300 to 700 mg per liter range, adjusted for how warm early May runs in Sioux Falls. Because you pass your gear so frequently, build a simple per-block plan (every 10 or 20 loops, take in X) rather than trying to carry everything at once.
⏵ Build your fueling plan
Get a carb, sodium, fluid, and caffeine plan per hour built for your weight and your goal time with the free ultra fueling calculator. Browse the rest of the free running tools at the tools hub.
⏵ Train for it with Summit Line
Get a training plan built around YOUR fitness and the kind of repetitive, sustained climbing a hundred-loop format demands. Summit Line reads your real training, builds the durability this race asks for, and rehearses your fueling so race day is something you execute, not guess at.
It brands itself, in its own words, "Sioux Falls’ Most Brutal Ultramarathon," and the format explains why: 100 loops of the same short hill at Tuthill Park, each about a third of a mile with roughly 90 feet of gain, stacking up to somewhere around 9,000 feet of climbing by the time you finish. There is no scenery to distract you and no long runnable stretches to recover on, just the same climb, a hundred times over. That kind of pure repetition is a different kind of hard than a mountain 50K, more mental grind than technical terrain.
The race’s own branding states 100 loops and 90 feet of gain. Reading that as a per-loop figure, which is the only reading consistent with a hundred-loop hill-repeat format, works out to roughly 9,000 feet of total climbing across the full 50K, all of it on the same short hill repeated a hundred times.
A 50K is about 31.07 miles, and divided across 100 confirmed loops that comes out to roughly 0.31 miles per loop, a very short circuit you repeat a hundred times. Short loops like this reward runners who can settle into a steady, almost meditative rhythm rather than those who need long stretches to find their pace.
Early May in Sioux Falls can range from cool to mild, and with a hundred short loops you will pass your own gear or a fixed aid point constantly, making this one of the easier ultra formats to fuel precisely. Aim for roughly 60 to 90 grams of carbohydrate per hour and sodium in the 300 to 700 mg per liter range, adjusted for the day’s actual temperature. Build your numbers with the free ultra fueling calculator before race day, and confirm the current aid setup on the official site.
The official site does not publish a cutoff time in its server-delivered content, and confirming exact race-day logistics requires checking the site directly, since much of it loads dynamically. Budget real time for a hundred-loop hill-repeat format and confirm the current cutoff and entry process with the race before you commit.
The short, flat-ish loop and constant access to your own gear make the logistics about as forgiving as an ultra gets, no long remote stretches, no complicated aid planning. But do not underestimate the mental side: running the exact same third-of-a-mile hill a hundred times is a genuinely different challenge than a varied trail course, and the race’s own "most brutal" branding is a fair warning. If you handle repetitive effort well and can pace patiently rather than chasing variety, this is a distinctive way to earn your first 50K finish.
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<a href="https://runsummitline.com/guides/tuthell-50k">The TutHell 50K course guide</a><iframe src="https://runsummitline.com/embed/race/tuthell-50k" style="width:100%;max-width:420px;height:180px;border:0;" loading="lazy" title="TutHell 50K course guide by Summit Line"></iframe>This guide is independent and for planning only. The course details, dates, and format come from public sources and can change year to year, so confirm the current specifics, including entry and cutoff details, with the official race before you register or run. The fueling and pacing advice is general and not medical advice.
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