Brooks updated its Glycerin by extending its proprietary midsole material—Brooks DNA—through the full length of the shoe. Brooks explains this material as follows:

Engineered from what's called a non-Newtonian liquid, this midsole technology responds to the amount of force placed on the foot and disperses the pressure, providing just the right amount of resiliency. Simply put, you can expect soft comfort when you want it, firm support when you need it.

Explanations like this make me nervous. There is no material that softens when you are heavier or run slower; yet hardens when you go faster or when you want a more active ride. Brooks isn’t the only company that employs this kind of text—K-Swiss spins a similar story for its Blade series—but I wish each company would refrain from explanations that strain the credulity of the reader.

But this doesn’t make the Glycerin 9 a bad shoe. On the contrary. I think it’s an excellent update and for a runner who thinks the new Gel Nimbus is just a bit too soft or too narrow they should give these new Glycerins a try.

Whereas the Gel Nimbus feels so soft it sucks most of the energy out of any attempt to run at speed, the Glycerin 9 feels soft-but-springy, rather than soft-and-energy-absorbant. It’s just more active than the Gel Nimbus 13. It’s also a little bit wider in the forefoot, and feels good to my foot when I put it on.

Fit is personal, but I found the Glycerin 9 supportive, due I think to the position of the laces and several overlays of upper material.

Although I’m not a heel striker I can certainly feel this is a shoe that will work for this type of running form, because of the bounce and spring. But Brooks is hedging its bet, and will soon launch its Pure Project—its first collection of natural running shoes.

The Glycerin 9 is a very good update, with lots of breathable material, and its proprietary BioMoGo sole material which degrades 50 times faster than most other midsole materials.

You can forget about the “Brooks DNA” mumbo jumbo, but acknowledge and be thankful for everything else in these shoes. You will have a pair of very cushioned and—for a neutral shoe— a very stable shoe to run in. They’re about as stable as you’re likely to find in the neutral category.

These shoes come in a men D width, in women B width, and in 2 specific men and women colors.