7 Best Ultra Running Shoes in 2025

How we test ultra running shoes

When we assessed the ultra shoes on this list, we got down to the tiniest details to ensure they weren’t a letdown. We purchased them ourselves to prevent bias and examined them thoroughly in our independent shoe testing lab. 

We also carefully follow these steps throughout our tests: 

• We run at least 30-50 miles in each shoe. We report everything that we feel and encounter while wearing the shoes during our tests.
• We cut them into pieces to scrutinize their parts. We also measure 20+ different features like stack heights, softness of the midsole, lug thickness, outsole durability, upper breathability, and so on
• We publish in-depth reviews that contain all our findings. Our lab data makes the shoes comparable by different features. Based on all of the tests, we select the best picks.

This guide applies to average trail runners and their needs. Because of this, we recommend cushioned shoes, mid-to-high heel drop, and so on. Of course, there are runners who run ultras in less-cushioned running shoes with a low heel to toe drop. However, that’s mostly reserved for more experienced runners who are well aware of the niche shoe categories and what they do for the legs and feet. 

We will mention this category but will not focus on it. 

What to look for in running shoes for ultras

We recommend looking for 5 things: 

1. Cozy fit that allows some swelling that will inevitably happen but also offers a superb lockdown 
2. Average-to-high breathability 
3. Durable toebox and outsole 
4. Avoiding zero or low heel drop, but looking for mid-range or high drop (higher than 5mm)
5. Superb cushioning: a lot of it (at least 30mm at the heel) + responsive 
6. Lugs and outsole thread patterns adequate for the terrain in question 

WANTED: cushioning

How cushioned should the ultra running shoes be? We recommend at least 30mm at the heel. This is, of course, based on average runners and not minimalist/barefoot enthusiasts who prefer the ground feel, even after 50k. 

In our lab, we measure the stack heights according to the guidelines from WorldAthletics. For this to be properly done, the shoe has to be cut in half which is, of course, what we also do. 

Now we know that just because the shoe is cushioned does not mean that it’s comfortable or responsive. Some foams are soft but dull, or squishy, or very responsive! Others can be too firm for your feet. 

Softness of the foam is something we measure in our lab. We use a shore A durometer to do that. 

Of course, more foam usually means more weight. It’s a balance we’re looking for. 

Heavier shoes slow us down but also bring more impact protection, so it’s about weighing your priorities and options. 

Choose a higher heel drop for ultra runs

Now that we’ve covered the stack heights, it’s impossible to skip the heel to toe drop. Runners who land at the forefoot or midfoot tend to choose lower heel drop, while heel-striking runners go for a high heel drop. 

During an ultra, our feet get tired and might appreciate any help they can get. Even forefoot strikers end up striking at the heel due to fatigue. So, some runners decide to run in a higher-drop shoe. As always, best to learn what suits you best while training for an ultra. 

Best upper for ultra running is the breathable one

First, it should be breathable. In our shoe lab, we test breathability by pumping the smoke into the shoe and watching where the smoke comes out and at which pace. Based on this, we assign a breathability rating on a 1-5 scale, where 1 is the least breathable. 

Of course, if you’re running in very hot weather, look for uppers rated with 5/5 or 4/5. If not that hot, 3/5 could also work. 

To understand this better, we look at the uppers under the microscope. 

It’s very interesting to see how the threads are intertwined, where ventilation holes are how big they are, whether the structure is loose or tight, etc. 

Dealing with swelling during ultra races 

Our feet swell even when just spending the day regularly, at work, with our families, etc. And they swell even more when doing hard work, like an ultra race.

Because of this, it’s important to choose a roomy shoe: one that will allow your feet to swell without creating hotspots and blisters, while at the same time providing a great lockdown. 

In most cases, we worry about cramping our toes as that can lead to bleeding, blisters, black toenails, and even worse. In the lab, we measure the width of the toebox in 2 places: where it’s the widest and at the big toe. 

To measure the width of the toebox, we first have to make a gel mold of the toebox. This allows us to get exact inner measurements and not measure the width on the outside (which would include the thickness of the upper)

The big-toe measurement allows us to understand how much the toebox tapers or how pointy it is. This is important because we all have differently shaped toes and want to find a shoe that fits us perfectly. 

It's also important to consider the toebox height. Especially when running on steep downhills, the upper can press on our toes and toenails. To avoid black toenails or blisters, consider higher toeboxes. 

Upper and outsole durability lab tests 

In ultras, durability matters much more than in short distances. The shoe really has to endure and we throw everything at them: mud, obstacles, debris, sharp rocks, water. Because of this, we recommend finding running shoes with very durable toeboxes and outsoles. 

To test the durability of both, we use a dremel. We press it against the surface, always using the same force, RPMs and duration. 

Testing the durability of the toebox in RunRepeat lab 

Once the damage is done, we assess it and rate on a 1-5 scale, where 1 is the least durable and 5 the most durable. 

Outsole durability test performed in RunRepeat lab 

When it comes to the damage done on the outsole, we’re able to precisely measure the depth of the dent with a tire tread gauge. 

Deeper dents tell us that the outsole is less durable and vice versa. 

Grip and lug depth in ultra running shoes 

Before running an ultra, it’s best to learn what type of terrain awaits you. Is it mostly a hard-packed trail, or are there any rocky sections, maybe it’s a fast soft-ground single track or a very muddy trail. 

There are 3 things that we can look at when it comes to the grip. First, the thread pattern. Then, the lug depth. Finally, the hardness of the rubber. 

When it comes to the thread patterns, we recommend: 

• A lot of closely spaced multidirectional lugs if you’re covering a bit of everything on varying terrain (both uphill and downhill)
• Deeper lugs (4mm and above) if you’re running on soft wet ground like snow or mud 
• Widely spaced lugs if it’s mostly mud as the distance between the lugs allows mud shedding 

Hybrid shoes usually have shallower lugs which is why they work well for road-to-trail adventures or very light, easy trail terrain that maybe even includes some roads. Here, we’re thinking of anything below 3mm. 

Versatile shoes used for moderate terrain usually have lugs that are 3-4mm deep. Keep in mind that there are other things that affect the overall performance which is why very bulky shoes don’t work well on technical terrain even if they have deep lugs, or why some very aggressive stiff shoes with somewhat shallower lugs excel on technical terrain. There is some overlap, for sure! 

For muddy trails, we recommend lugs that are at least 4mm deep. 

Finally, we can look at the hardness of the outsole - harder rubber is more protective and durable, while softer rubber is more flexible and stickier. 

Changing the shoes mid-race 

Some runners change their shoes mid-race. This happens for many reasons: 

• their feet got swollen a lot and now they need something with a wider/longer fit;
• some critical parts got destroyed, like an eyelet, lugs, upper; 
• their feet got too wet and the shoes can’t dry easily so they jump into the dry spare pair;
• they had to treat a wound or a blister with a lot of tape which made the feet wider; 
• their feet are too tired and need a bit more cushioning now or a higher heel drop; and so on. 

It’s always good to have a spare pair ready, but what features it should have (the same pair as the one you started the race in, or the one that’s a little wider, more cushioned, higher heel drop, etc.) that’s on you to find out while training for an ultra. 

How socks can help?

From our experience, it’s best to use socks that are not made of cotton. They have no moisture-wicking properties, they do not dry quickly. 

Many prefer wool or bamboo socks. Compression socks work wonders for some of us, but we don’t recommend trying them at the ultra race first. It's best to test them in advance. You might enjoy the compression only at the feet, while other runners prefer knee-high compression socks or even compression shorts. 

The important thing is that socks should not create bumps or layers that would irritate your feet. They should fit perfectly. You might appreciate a change of socks mid-race, maybe even more than once, so best to pack a few spares! 

Injinji socks have been gaining popularity. They might look odd with every finger having its own “sock” but they do the job well and we see them more and more on racers’ feet.