Glycerin Flex Specs
Best For- Daily training, gym trainer
Category- Neutral
Weight- 8.8oz (Men's US 9)
Drop- 6mm
Stack Height- 36mm (heel) / 30mm (forefoot)
What's Similar? Brooks Glycerin 23, New Balance Ellipse V1, Hoka Mach 7
What does Avery think?
Brooks’ brand-new shoe really puts the “Flex” in Glycerin Flex. If you’ve been a Brooks fan, this shoe won’t disappoint, and if you’ve never ran in the brand before, this is the perfect shoe to start with. This shoe is “flexible” in every sense of the word. The first thing you’ll notice when you put it on is the large horizontal chasm running across the entire midsole, separating the foam into two sections. This design allows the shoe to almost bend in half, creating a truly adaptive feel that moves with your foot and hugs it through each stride. Beyond the design, the Flex is also versatile in how you can use it. You can wear it for long runs, short runs, slow miles, or faster efforts, but it also transitions well into the gym.
The Good
I found bodyweight exercises like lunges, air squats, and dynamic stretches felt great since the shoe isn’t stiff at all. The knit upper adds to that experience, giving the shoe a fitted yet relaxed feel. With its four-way stretch, the upper moves with you and molds to your foot as you go. Although the Flex is a continuation of the Glycerin line, the two don’t compare all that closely. I’d describe the Glycerin 23 as a max-cushioned daily trainer, whereas its new counterpart, the Glycerin Flex, is more versatile, firmer, lighter, and much more flexible
My Tweaks
I’ve never been a Brooks fan on my runs. I use the Ghost 17 exclusively for walking and do enjoy it, but the Glycerin Flex surprised me. Runs felt natural and smooth. That said, I personally prefer a softer, more cushioned forefoot, and the Flex doesn’t quite deliver that plush feel I typically look for in a running shoe.
Summary
The Glycerin Flex is a strong new addition to the Brooks lineup. If you’re looking for a lightweight daily trainer, a flexible and stable gym shoe, or something that can handle both, the Flex is a great option.
What does Alex think?
The Glycerin Flex is Brooks latest take on the existing Glycerin line of models. The
Glycerin exists as a max cushion daily trainer the uses a “tuned” version of their
nitrogen infused DNA midsole foam. The Glycerin Flex has the same tuned DNA foam
but adds a new upper and some unique cuts in the midsole. The name flex designates
both the more flexible midsole, but also the dual-use nature of the shoe. It is supposed
to be a gym-worthy version of the Glycerin that keeps the same soft ride but adds some
features that make it more usable for non-running activities.
The Good
The first thing I noticed right out of the box was the look of the shoe. The midsole looks
phenomenal with the added cutouts and flared forefoot. The upper is sleek, reminiscent
of the Glycerin Stealthfit with its smooth, knit mesh and integral eyelets. I see this shoe
selling well as a lifestyle option for many people, keeping the comfort that is standard for
a Brooks shoe, but adding a stunning look that Brooks models sometimes lack.
Running in the shoe was a blast. The ride is soft and the added flexibility in the midsole
makes it feel so natural and smooth. The toe-box is roomy, and the flared portion of the
forefoot felt stable. The upper is soft and light, providing a secure lockdown on my
narrow, low-volume foot. I’m usually wary of non-traditional, one-piece uppers because
they’re often baggy on my foot, but I had no problems with the fit of the Glycerin Flex. I
had it on the treadmill for testing (Midwest winter life…), and it was significantly quieter
and less “cloppy” than other models I’ve tested recently. Brooks’ DNA foam has always
been a stiff and responsive material, but the shape of the midsole helped it feel much
softer than a regular Glycerin.
My Tweaks
I have very little to tweak about this shoe. My only comment is that this shoe is
marketed as a sort of “cross-trainer” that a customer could use in non-running exercise
applications. It certainly could do that, in the way that any shoe can be used for anything
if you’re willing. I found it a little too soft for any weightlifting or lateral motion activities.
As a general rule of mine, a shoe is either good at running, or good in the gym, but
rarely both. I do however appreciate a “running focused” cross-trainer because the
opposite is usually true about shoes in this category.
Summary
The Glycerin Flex is special. I was pleasantly surprised at how fun it was to run in and
stunned by its look. This will continue to be a member of my daily rotation.
