I ran 40 miles in the Salomon S/Lab Ultra Glide trail-running shoe — here's my verdict

Tom's Guide

26-05-2025

The Salomon S/Lab Ultra Glide is a long-distance trail-running shoe designed to offer a comfortable ride thanks to the high level of cushioning in the midsole and the innovative RelieveSphere outsole.
It's one of the best trail running shoes you can get if underfoot comfort is your priority, especially if you have epic ultramarathons in mind, but the price is very high for a shoe that doesn't have a carbon plate in the midsole, and I'm unconvinced the S/Lab Ultra Glide does enough to merit this high price.
In my Salomon S/Lab Ultra Glide review I'll explain why I enjoyed my runs in the shoe, but why cheaper options like the Hoka Speedgoat 6 will offer better value to most runners.
The Salomon S/Lab Ultra Glide launched in early 2025 and costs $250 in the U.S. and £230 in the U.K., making it one of the most expensive trail-running shoes available. It's not to be confused with the Salomon Ultra Glide 3, which shares some features but uses less impressive midsole foams, and is the cheaper option in the line.
The S/Lab Ultra Glide is currently only available in the red and white color I tested, which are the usual colors Salomon uses for its performance-focused S/Lab shoes.
While I found that the shoe fit me well for length in my normal size, and the quick-lock laces create a secure fit and are easy to adjust, I didn't love the stiff collar at the back of the shoe, which didn't always feel comfortable.
Standing 41mm tall at the heel and 35mm at the forefoot for a 6mm drop, the S/Lab Ultra Glide has an exceptionally high midsole stack for a trail shoe.
Despite this, it's not as heavy as you might expect, weighing 10.8oz in my US men's size 10, which is due to the lightweight foams in the midsole.
The upper of the S/Lab Ultra Glide uses two materials, with a stretchier and softer material around the forefoot and a stiffer one at the back.
There is some padding around the tongue and collar, and quick-lock laces you secure with a toggle that you can then pop inside a lace garage — a pouch on the top of the tongue — so it doesn't bounce about.
While the underfoot comfort of the shoe is good, I didn't love the feel of the upper during my runs, especially the high, stiff collar at the back of the shoe.
It was always noticeable and rubbed my Achilles a little on my first few runs, and although it never became a major problem for me, I'd be wary of it if lining up a very long run.
The S/Lab Ultra Glide uses two foams in its midsole with a softer, springier core of EnergyFoam+ surrounded by a frame of EnergyFoam, which cradles the foot thanks to the hide sidewalls at the back of the shoe.
This dual-density system is designed to create a bouncy and comfortable ride while remaining stable — you don't want the midsole foam to be too soft and wobbly on uneven trails.
The wavy outsole design on the shoe creates concave shapes in the bottom of the shoe that are placed at pressure points to try and create a more comfortable ride for ultra-distance trail runs, in particular.
It's an innovative idea, and the S/Lab Ultra Glide is certainly comfortable, but it does limit the amount of chevron-shaped lugs that can be placed on the bottom of the shoe, since they can't be put where the outsole caves in.
However, grip has not been a problem for me when running in the S/Lab Ultra Glide, and unless you're planning to run in deep mud, there is enough traction to be confident running fast in the shoe.
I ran in the S/Lab Ultra glide on a mix of terrains, mostly in my local forest on hard-packed paths and gravel, along with rooty and muddy single-track trails.
While it doesn't have a carbon plate in the midsole, it still felt quite stiff to me on my first couple of runs, and even after breaking in, it isn't as flexible as lower-stack trail shoes.
It is undoubtedly very comfortable, though, with the combination of foams in the midsole delivering a soft and protective ride. While I didn't hit ultra distances myself in the shoe, I used it a lot with very tired legs in marathon training and the high level of cushioning was welcome.
The RelieveSphere design on the outsole would come into its own more on very long runs, I expect, but it does add some flexibility to the outsole and helps with grip and ground feel on uneven terrain, which was a concern for me with the high stack.
Despite this high stack, the S/Lab Ultra Glide never felt unstable for me, and I felt comfortable flying downhills even on uneven ground. Although it's a larger shoe, it also didn't feel too heavy when climbing hills. The ride ticks over smoothly in a way that would help you keep going during long events.
It's not a nimble shoe, however, and on twisting, narrow paths, it could feel a bit cumbersome when running at faster paces. This wasn't a problem at the slower speeds most of us would run ultramarathon events at, though.
During all of my runs, the grip from the shoe has been reliably good, and the outsole also provided traction on wet roads to and from the trails. While it might not have enough bite for runs on mud or grassy hills, the Salomon S/Lab Ultra Glide will handle most terrains with ease.
The S/Lab Ultra Glide is a highly comfortable shoe for long runs that has some interesting ideas behind its design. But it's very expensive, and I didn't find its performance significantly better than cheaper shoes.
I'd look at the Hoka Speedgoat 6 as an equally capable if slightly less cushy trail all-rounder for less, and if you did want to splurge on a fast trail shoe then lighter, carbon-plated options like the Hoka Tecton X3 or Adidas Terrex Agravic Speed Ultra do deliver a speedier ride, though are also less stable.
If you like the idea of a big stack of foam underfoot and stick to tamer trails and road-to-trail runs, then the New Balance Fresh Foam X Hierro v9 is a good option as well.
While I like the idea of the S/Lab Ultra Glide as a comfort-focused option for ultramarathoners who aren't at the front of the pack using carbon plate trail shoes, the price just feels too high to hit that niche.