Dynafit Ultra 100 is another trail shoe from the brand designed for ultra trail runners, and I think there are 2 standout features that are particularly well-executed:
1) The thick, soft, yet not mushy foam midsole
2) The heel counter that provides excellent ankle support
These 2 features are ideal for ultra-distance running because a foam midsole that is too thin will cause foot fatigue over long distances, while one that is too soft reduces agility. When running for long periods, a heel counter that helps support the ankle can significantly reduce the risk of ankle sprains.
Before we get into the review, let's look at the specs of the Dynafit Ultra 100 to see what the brand has offered.
Based on the specs, compared to the Dynafit Ultra DNA , you can see that this model offers more support and a lower drop, meaning it's less about speed and more about finishing the race.
Upper Construction
There are 2 features I like: the lacing system and the heel lock.
The first lace hole features an A-shaped TPU structure that helps wrap and secure the foot when tightened, providing a secure fit while running. It feels very stable when running. The middle section looks like fabric covering the laces, but it's actually a channel for neatly tucking away the lace ends when tied. This is both a pro and a con, as it makes lacing up more difficult than usual.
Heel Preload is a very important feature of this model and is designed specifically for ultra runners, or runners with weak ankles who are prone to sprains. This model is a great fit for them. The heel structure fits snugly around the heel and is quite rigid, providing excellent ankle support and enhancing stability when stepping on uneven or slanted surfaces.
The brand hasn't specified the upper material, but it feels like typical trail shoe fabric and seems tough and durable.
The toe box is neither narrow nor wide, but the toe volume is low. Those with wide forefeet or high insteps will likely need to size up significantly.
The toe bumper is quite sturdy, so you don't have to worry about kicking rocks or roots. It provides excellent toe protection. The outer material is TPU-coated, making it very durable.
Lower Construction
The foam midsole is another highlight of the Dynafit Ultra 100. It offers the perfect balance for ultra distances. The foam feels soft without being mushy, and there is minimal compression upon impact. This is another reason it doesn't cause foot fatigue during long runs, as it distributes body weight more evenly across the sole than softer foam that compresses more. The 26–32 mm foam thickness is just right—neither too thin nor too thick. Its firm density also helps absorb impact and reduce pressure from rocks.
The shoe also has a rocker shape, which makes the stride even smoother.
The outsole is made entirely of Vibram Megagrip, with no cutouts to reduce weight and small lugs all around the tread. These Traction Lugs help improve grip on dirt.
Running Experience
The first time I put them on, it felt like being a real athlete. The fabric feels stiff and the upper structure rigid, but it also feels secure. I think this is due to the excellent wrap around the instep and heel, and the ability to stand with a full foot strike. The shoe offers very good stability.
I wore them for several training runs at Khao Phang and Doi Tapang. The trails were extremely rugged, with loose rocks and concrete sections. I can guarantee that the stability prevented my ankles from spraining. The Heel Preload provided excellent ankle support, while the relatively wide midfoot base made foot placement feel secure.
The foam midsole didn't feel mushy even after long runs. It didn't cause foot fatigue when encountering loose or sharp rocks. I had no concerns about grip, which was excellent on both steep dirt trails and concrete surfaces. I felt confident with every step. Vibram Megagrip is reliable.
Running on flat ground was also easy. It's a supportive shoe that still offers a good rolling motion, although not as much as a road shoe.
What I like most about the Dynafit Ultra 100 is the confidence it provides when running on any surface, no matter how difficult the terrain.
Durability
I'm quite confident that they are very durable. As I mentioned earlier, the training trails were quite harsh, yet after a cumulative distance of about 60 km, I saw almost no wear on the tread. They still look like new, and the other materials also look normal.
Sizing
This may be an issue for many people, as the shoe is 0.5 cm shorter than other brands and has less toe box volume compared to the same size.
My feet measure 25.5 cm long and 10.5 cm wide. I usually wear a 27 cm shoe. For the Dynafit Ultra 100, I had to wear a 28 cm (10 US) size, leaving about 1.5 cm or a thumb's width of space at the toes. Therefore, I recommend sizing up by one size for the Dynafit Ultra 100.
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Dynafit is available at Runnercart: Click