I’ve been running in the Brooks Glycerin Flex for the past few weeks. At first glance it looks like a familiar Glycerin, but once you start running it quickly becomes clear that this version takes a slightly different approach. Many modern running shoes rely on an aggressive rocker or extremely soft cushioning. The Glycerin Flex instead focuses on flexibility and a more natural feel underfoot.
What stood out to me most is that the shoe doesn’t try to force anything. It supports you, but still lets you do the work. You stay connected to the ground while the shoe still provides enough comfort for longer distances. After about 60 kilometers of testing in and around Munich, it became clear where this running shoe performs best and who it suits most.
Comfort & Fit
As soon as you put the shoe on, the upper material immediately stands out. The engineered mesh feels soft and comfortable. In the forefoot it wraps around the foot almost like a sock, while the midfoot provides a bit more structure and support. The toe box feels just right to me. Not too wide, but definitely not tight either. I have noticed that with other running shoes before.
I normally wear a size 44½ and tested this shoe in the same size. The fit is true to size and offers enough room, even for runners with slightly wider feet. Around the heel the shoe feels secure without creating pressure points, and thanks to the extra lace hole you can lock the heel down even more if needed. Even when the pace picked up, my foot stayed firmly in place. Comfort also holds up well over multiple kilometers, without pressure points or irritation, even when your feet start to warm up during a run.
Ride & Cushioning
The first thing you notice while running is how flexible this shoe feels. And the name already suggests that. The sole moves naturally with your foot and the transition feels smooth and fluid. It creates a dynamic ride without ever feeling unstable. The Glycerin Flex has a 6 mm drop, which suits my running style well since I tend to land more on my midfoot and forefoot. The transition into toe-off feels natural, allowing you to run a bit more actively while maintaining a slightly more upright posture without adding extra strain during longer runs.
Brooks uses what they call DNA Tuned foam in this shoe. What you notice most is that the cushioning remains consistent. The heel feels slightly softer, while the forefoot offers a firmer and more responsive push-off. Even after several kilometers the shoe still feels lively and does not feel compressed or fatigued. The slightly wider platform in the forefoot adds stability during push-off. Especially here in and around Munich, with its elevation changes, I noticed this most on downhill sections. Running downhill feels controlled and stable underfoot.
At the same time, it becomes clear that this is not a shoe designed for maximum stability or an extremely soft, floating ride. That is simply not what it is meant for. The Glycerin Flex feels more direct and natural than some other models in this category. For runners looking for a flexible training shoe, that can actually be a real advantage.
Who is this shoe for?
The Brooks Glycerin Flex is mainly a shoe for everyday running and longer runs. I would also have no hesitation using it for a half marathon. It also works well for Hyrox training. The shoe stays agile while running and still provides enough stability for other workouts.
If you are looking for maximum stability or an extremely soft and plush ride, this probably is not the shoe for you. For fast intervals or races, I would personally reach for something like the Brooks Hyperion Max 3 instead. With a price of around €180, the Brooks Glycerin Flex sits in the higher price range. It is not cheap, but you are choosing this shoe for its flexibility and control rather than maximum cushioning or pure speed.
