By Brian Metzler

When it comes to running shoes, we’ve entered an age where not only “more is better” but apparently much, much, much more is better. I’m talking about midsole foam stack heights. Although it’s been 15 years since Hoka’s first maximalist shoes debuted and about five years since the widespread advent of chunky, max-cushioned racing models, shoes are still getting taller. It’s now in vogue to wear shoes in training that are even thicker than the ones you wore in your last marathon.

There have been numerous shoes in recent years that have towered over the 40mm stack height standards (that World Athletics says is the limit for elite racing shoes), including the Adidas PrimeX Strung 2.0, Asics Superblast, and Hoka Skyward X. Those kinds of shoes have created an entirely different stride sensation than even the more moderately cushy shoes that were popular just a few years ago. Whether you want to call them “illegal shoes” or mega-max trainers or super troopers, they all offer a high-off-the-ground, and semi- propulsive vibe for a variety of training runs. 

Now there’s one more compelling behemoth in the mix, as the new Brooks Glycerin Max ($200) launched recently with the latest nitrogen-infused super-critical midsole foam in the Brooks arsenal and a 45mm stack height under the heel. Once you lace up these cartoonish-looking shoes and start running, that newfangled foam serves up a juicy feeling under your feet. It’s soft and bouncy and plush and it could be a game-changer for Brooks. 

What’s New: The Glycerin Max is a brand new shoe, part of Brooks’ following the trend of super high loft training shoes first pursued by Adidas with its original PrimeX Strung two years ago. It’s built on a very chunky two-part nitrogen-infused DNA Tuned midsole with a GlideRoll rocker geometry. Other key components include a soft and stretchy engineered mesh upper and a sufficient amount of rubber on the outsole to give it grip on dry and wet pavement.

Fit/Feel/Ride: The Glycerin Max fits true to size with a medium-volume interior that has plenty of extra room in the forefoot for toes to wiggle and splay. It has a very cushy plush interior, with soft padding on all sides of the foot, including around the heel collar, in the thickly cushioned tongue, and from the premium sockliner under the foot. That cozy step-in sensation continues to feel luxurious on the run, as it is one of those shoes in which your feet are wrapped with cushiness in every stride at slower and faster paces. (The soft, breathable upper is exceptional and one of the keys to providing a secure fit for a wide range of foot shapes, including my narrow feet.) That extra cush though, tends to mute the feel for the ground and limit its agility. But the ride is still buttery smooth and moderately bouncy, and although very stable, it’s also a bit cumbersome until you get used to it.

Why It’s Great: It’s great because it feels so opulent the moment you slip it on and lace it up. The cushiness surrounds your feet, providing a very fluid vibe, especially at slow to moderate paces. But part of that plush feeling is also tied to performance. It feels great under your feet, but it also puts some zing in your stride. The secret of the DNA Tuned midsole is that there are different cell sizes that create softer landings in the midfoot and a firmer, more responsive feel in the forefoot. The foam isn’t mushy so it doesn’t bottom out, but instead has some structure to it that always bounces back. The rockered profile works in concert with the differential of the foam, creating a cushy, springing, and undoubtedly fun, energetic ride.

Specs

Weights: 9.1 oz (women’s 8); 10.5 (men’s 9)

Heel-Toe Offset: 6mm; 45mm (heel), 39mm (forefoot) 

Why You’ll Love It: You’ll love it because it feels so good and it has a tiny bit of versatility. It’s good for long runs at slower to moderate paces, and it’s a gem for recovery runs and midweek maintenance runs. Can it pick up the pace and move slightly faster? Yes. Slightly. It’s a giant max-cushioned trainer, but it is responsive enough to hold its own at cruiser pace – somewhere in the range of upper Zone 3 and lower Zone 4 pace zones. I quickly found this shoe’s limit when I was playing around with a variety of paces on fartlek-style repeats. It took quite a bit of effort to ramp it up to a semi-fast pace, but once it got there the propulsive bounciness seemed to make it easier to maintain. But let’s just say I wouldn’t try to do a tempo run in it, and nor did I find pre- and post-run strides to be very compelling.

Pro: It’s infinitely bouncy and squishy, which makes it easy on the muscles and joints in your lower legs. I’ve found it to be a shoe that speeds up recovery time. The day after a long run, my legs didn’t feel fatigued at all.

Con: It’s not as light as I’d like it to be, and that’s the big limiting factor on this shoe’s lack of ability to run faster paces. I love the foam, but if this shoe was about 1.5 to 2 ounces lighter, I think it could go a lot faster. It could shed some weight with less rubber on the outsole, but most of the weight comes from the chunky midsole.