Dynafit Ultra 100 Review: A trail running shoe for long distances, offering exceptional comfort and a light, agile ride for all-day fun

Have you heard of the outdoor brand Dynafit? With a clear concept of "By athletes, for athletes," the brand is brimming with a tireless pursuit of functionality and an innovative mindset, creating gear that allows all mountain endurance athletes, active year-round in both summer and winter, to perform at their best. Today, the brand supports athletes from around the world in a wide range of disciplines, including ski mountaineering (skimo), trail running, mountaineering, and cycling

Dynafit is one of the top brands in Japan and has many fans in the field of winter activities such as backcountry skiing, but until a few years ago it may not have been very well known in the trail running community, even on a global scale

I will never forget that I first encountered this brand's trail running shoes at an outdoor trade fair in Germany in 2016. This was the exact timing when the brand announced that it would be entering the trail running market from the 2017 Spring/Summer season

Since then, Dynafit's trail running shoes have continued to evolve steadily, but unfortunately I have never had the opportunity to actually try them out, so until I came across the shoes I'm introducing today, I had no idea how well they performed.To be honest, I only had a prejudice that they were probably hardcore alpine and racing-style running shoes for connoisseurs, for better or worse

Now (I've already run over tens of kilometers in these shoes), I can't stop wearing them every day because they are incredibly comfortable and allow me to run long distances. They offer cushioning and support without the bulky, unstable feel or weight that is common in traditional cushioned shoes, and they respond very quickly. Their high performance has me constantly wearing them

this hidden diamond in the rough, the Dynafit Ultra 100 , on an actual trail, so I'd like to share my review right away.

Key Features of the Dynafit Ultra 100

The Dynafit Ultra 100 is a trail running shoe designed for long, comfortable runs on a variety of trails, including steep, muddy, and rocky terrain. The highly breathable and durable upper provides an exceptional fit. The midsole offers ample cushioning while providing a lightweight, sensitive feel, excellent energy return, and stability for comfortable long days on the trail. The outsole features the latest Vibram MegaGrip & Traction Lug technology, which provides traction even on wet rocks, ensuring a firm grip and a secure grip on the ground, allowing you to confidently step on tough terrain and steep climbs and descents. With everything you need to traverse the mountains with ease, the Ultra 100 is ideal for ultra-long distance races, speed hikes, or simply as a cushioned off-road shoe.

Recommended points

• A midsole that combines outstanding cushioning with the resilience to allow for firm stepping
• 4mm deep Vibram MegaGrip & Traction Lug technology for superior grip in all directions, even on technical terrain
• A comfortable upper that provides ample room while providing a flexible and comfortable fit
• The "Heel Preloader" system provides excellent heel hold for a stable landing
• 6mm drop for heel cushioning and natural stride
• High durability that won't wear out even after long distance driving

Points of interest

• It doesn't feel heavy, but it's not particularly light for an ultra-long distance shoe
• If you wear it in the same size as usual, it will be a little slim, so it is best to choose one size larger than usual

Main specifications and evaluation

Detailed Review

Upper construction (appearance, size, fit, durability)

As the name suggests, the Ultra 100 is a shoe designed for ultra-long distances of 100 miles or so, known as "ultra trails." What's needed in a shoe for running almost all day is a comfortable fit that doesn't become a burden even when worn for long periods of time, cushioning that can withstand tens of thousands of impacts without fatigue, and toughness that won't break down on off-road terrain. Unlike shoes that prioritize speed, shoes for long distances tend to be bulky, chunky, and ungainly. Considering this, the Ultra 100 has a thick sole, yet has a sophisticated and stylish appearance, and the color scheme, which consists of monotone and accent colors, is also tasteful, and I was impressed with it right from the start.

Before putting my feet in, I was concerned about the sizing of these shoes. They seem to be made slightly small (slim?), though not extremely small. I usually fit comfortably in a US 9 (27cm) size, but this model fit perfectly in a US 10 (28cm). However, there was no excessive extra space in the toes, and as long as I adjusted my feet properly and chose the appropriate size, there was no problem. However, I do have a unique foot shape, so I recommend trying them on before purchasing to make sure the size is right for you

The first impression I got when I actually put my foot in was a snug fit from the arch to the instep, and a firm hold on the heel. At the same time, the mesh fabric stretches just enough so it doesn't feel too tight, and there's plenty of room for the toes to move in the forefoot, giving it a good balance of precision and play, which is not a bad feeling. Even though they're designed for long distances, there's no need to worry too much about it; they'll lead you on a comfortable trail no matter what distance or terrain you wear them on

This mesh fabric is highly breathable, allowing you to feel cool air entering through your toes while running, effectively controlling the temperature inside your shoes, which can heat up when you start running on hot days (see photo below)

The shoe tongue is generously padded, providing a soft and comfortable feel against the instep, and the soft, tubular laces can be easily tightened by simply pulling from the top or center. The moderate friction of the shoelace holes prevents the shoe from slipping off afterwards (see photo below)

There's also a stretch mesh lace guard on top of the tongue that can store the knot and shoelaces while also tightening the instep just enough. This protects the shoe from pebbles on the trail, and storing the shoelaces here prevents them from getting caught or loosening, so (thanks to the good fit of the shoes themselves) you don't have to retie your shoelaces as often. I also like how hiding the shoelaces makes the shoes look neater

The toe area is roomy, but the reinforcing white overlays around the base of the toes work in conjunction with the laces to moderately prevent movement, so your feet don't slip around inside the shoe, even when descending, giving you peace of mind (see photo below). This heat-bonded reinforcement is thin and lightweight, but there's no need to worry about it rubbing against rocks and tearing, and it provides solid protection around the shoe. However, since these aren't hiking boots, they're not designed to withstand heavy weights or intense impacts

The heel is equipped with a band-like "heel preloader" that wraps around the back of the heel counter, preventing your foot from moving around inside the shoe even when you land hard, and there's no feeling like your heel is going to slip out when you walk, making for a very comfortable fit. I was honestly surprised by the firm hold, support, and stability around the heel

Overall, the comfort and precise fit make these boots ideal for hard, technical terrain, and I felt confident wearing them even on long days in the mountains or running on rocky terrain

The heel opening is padded for comfort

Running comfort when actually wearing them (focusing on the midsole and outsole)

A well-balanced midsole structure that provides just the right amount of rebound and stability without compromising superior cushioning

This is good news for those who want as much cushioning as possible but don't want to run on marshmallows and prefer moderate feedback from their shoes

The EVA midsole, which has been significantly revised from the previous model, provides ample cushioning (the stack height is a thick 32mm), giving you the solid feeling that your feet are sinking into the rich foam

However, that doesn't mean it's simply too soft; it feels like it has a fair amount of resilience. The midsole is in the medium range in terms of hardness, but there seems to be a hard plate inside the midsole up to the ball of the foot, which makes it resistant to upward thrusts from below and responds well when you step hard on your foot to accelerate. Conversely, it may not be suitable for speed-focused runners who want strong resilience, or minimalists who prioritize delicate soles (although these shoes are not designed for those styles in the first place)

Another thing I like about them is that they have excellent cushioning, yet are very stable, so you don't feel unstable even when landing

This is probably due to the aforementioned "heel preloader" structure that firmly holds the heel, and the base (wide outsole) that extends slightly outward from the size of the foot. Either way, this is a the Ultra 100 , and there's no doubt that it's the reason why you feel more stability and agility than you'd expect on technical terrain.

The drop is 6mm, which balances natural foot movement with forward propulsion from the ground up. It's just right for long distances. Furthermore, the sole has a boat-like rocker shape from the heel forward, which smooths the stride from landing to pushing off, while also absorbing continuous impacts over long distances

Vibram MegaGrip and Traction Lug technology combine for stronger grip than ever before

the Ultra 100 provided a firm grip and was less likely to slip when going up and down steep slopes, or on technical trails with rocks and mud. The main factor that makes this traction possible is, of course, the outsole structure, which combines Vibram's MegaGrip and Traction Lug technologies.

Simply put, "Vibram MegaGrip" is a rubber sole that provides incredibly sticky grip even on slippery wet rocks. The new "Traction lug technology" introduced a few years ago is a complex lug structure that increases the surface area by up to 50% by adding steps or increasing the number of protrusions (the bumps in the photo below) to each lug on the sole, thereby increasing traction by up to 25%. The Ultra 100 combines these two technologies to achieve top-class traction that provides a firm grip on even the toughest terrain

I ran the Ultra 100 on a variety of terrain in Okutama, Tanzawa, and Nasu, including steep gravel roads and trails, mud, tree roots, wet rocks, scree, and paved roads, and the outsole, dotted with 4mm chevron (inverted V-shaped) lugs, gripped the trail firmly in every situation. Unless the road was extremely rough, I was able to land confidently and push down powerfully, and I think the effect is particularly noticeable the more technical the terrain

Summary: It's too good for athletes. A reliable partner that combines gentleness and strength to support you on long, arduous journeys

I was pleasantly surprised by the performance of the Ultra 100, a long-distance trail running shoe from Dynafit that has not been widely known in Japan until now. Whether I'm running long distances on the trail or wearing them all day as everyday shoes, they remain comfortable for a long time

As long as the shoe fits my slightly tricky foot shape, it has a comfortable fit with few quirks overall, and its excellent cushioning and protection, smooth and stable ride, and reliable grip make it comfortable to wear for a wide range of purposes, from off-road training to technical ultra races (and of course as everyday outdoor shoes). I haven't actually run 100 miles in it, but from what I've done over the last few dozen kilometers, I can imagine that it will also show its true value in hard long-distance runs

Dynafit is not yet a well-established brand in Japan, but in Europe it is a highly regarded high-performance brand supported by serious top athletes. Honestly, after trying them out, I never expected them to fit me so well. I truly feel like I've found a diamond in the rough. These incredibly versatile running shoes perform well no matter where I wear them or how far I run. They're sure to become an indispensable partner for me on my long, arduous journeys for the foreseeable future.

For more information and to purchase the Dynafit Ultra 100

For more information about the Dynafit Ultra 100 product, please visit the official website

You can also try on the actual products at Kandahar Yama no Mise, located in Kanda Jinbocho, Chiyoda Ward, Tokyo (as of June 13, 2024)

   

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