Brooks Glycerin Flex Review

Specs

Price

$238

Weight

258 grams (men’s US 9/UK 8)

Pronation Control

Neutral 

Stack Height/Drop

36 mm heel, 30 mm forefoot/6 mm drop

Introduction  

The minimalist running shoe movement is ancient history now. Back in the late 2000s, Christopher McDougall’s Born to Run convinced a generation of runners that their cushioned trainers were the enemy, and brands scrambled to respond with thin soles and barefoot designs. 

Then the pendulum swung the other way. Hoka arrived with its thick, rockered foam slabs, the industry followed, and suddenly flexibility was out and stiffness was in.

Brooks has spent years trying to thread this needle. Their Pure line in 2011 was an attempt at natural-feeling footwear, but it didn’t stick. 

The Glycerin Flex is their most compelling answer yet- a daily trainer that piles on the cushioning without locking your foot into the rigid ride that defines most modern shoes. 

Almost all of the best running shoes released these days follow the maximalist trend, with stiff, rockered rides that are controlling in how they hold the foot and guide running gait- making the Glycerin Flex’s approach genuinely unique.

The Good 

The flat knit upper of the Glycerin Flex is superb. The sock-like design conforms to your feet and provides a really comfortable, locked-in feel. The fit is true to size and the material stretches to give you a more accommodating fit if you have wide or high-volume feet.

The Glycerin Flex has a DNA Tuned midsole which means that there are 2 different foam densities. There's a firmer foam situated in the forefoot which provides a firmer platform to push off from- this helps to prevent it from feeling overly mushy.

DNA Tuned is a supercritical EVA which means that the EVA is infused with nitrogen. This makes the midsole lighter and more lively. It doesn't feel as energetic as Brooks’ DNA Gold which is a PEBA foam but DNA Tuned is a lot more durable and more suited to slow running.

The ride of the Glycerin Flex is a natural one and you get the feeling that you are in control of the shoe; not the other way round. The thick, deep grooves between the pods in the forefoot and midfoot allow your feet to move freely. 

The Glycerin Flex strengthens your feet. The flexible forefoot increases muscle recruitment and training load, which over time contributes to stronger feet. Your feet have to work harder, which is the point of the design.

The Not So Good 

The Glycerin Flex is not a fast shoe due to how bendy the forefoot is. This makes it difficult to pick up the pace so the Glycerin Flex is suited to mainly easy and recovery runs. There are better trainers for doing tempo runs and workouts. The Flex also doesn't have a forefoot rocker so transitions are more relaxed.

Conclusion 

The Glycerin Flex stands out as a truly unique offering in a sea of stiff, maximalist trainers with no ground feel. It's a modern day, minimalist trainer that allows your feet freedom to move while providing just enough cushioning to protect them. 

While it has “Glycerin” in its name, it has very little in common with the regular Glycerin and Glycerin Max. It has much more ground feel, no rocker and it's less structured. 

In the Glycerin Flex, you still get that polished, signature Brooks fit and feel. It feels like a lot of thought went into its design- the way it flexes and bends without any stiffener but still offering enough support. 

The Glycerin Flex is a trainer for runners who want a natural, flexible running shoe with plush cushioning. It's for runners who don't want a heavily guided gait. 

In a Brooks rotation, the Glycerin Flex can be your easy or recovery option for relaxed running. You can use the Hyperion Max 3 as your speed trainer and the Hyperion Elite 5 for tough workouts and races.

Reviewed by Brandon law

Check out Brooks Glycerin Flex here