The Glycerin Max is a brand new trainer and is a spinoff series of the popular Glycerin. It has the thickest midsole of any Brooks trainer and it's designed to be Brooks' softest, plushest trainer. It costs $200

The Glycerin is on its 21st version and is one of Brooks' most popular Brooks running shoes. It's a max cushioned trainer for easy and recovery runs. It costs $160.

This comparison will tell you which version is better for you.

The Glycerin Max uses Brooks’ newest midsole foam in DNA Tuned. It’s a supercritical EVA foam designed to be soft but also lightweight. The Glycerin 21 uses Brooks’ tried and tested DNA Loft v3 which is also a supercritical EVA but it’s denser and heavier than DNA Tuned.

The Max has a slightly softer ride than the 21 thanks to its midsole foam. It has more long-distance comfort and it has better impact protection than the 21. The 21 has a more balanced ride capable of a wider range of paces. It can handle speed better than the Max.

The Max also has bigger cells in its rearfoot for softer landings while it has smaller cells in its forefoot for firmer toe-offs. The Glycerin 21 only has a single-density midsole with the rearfoot and forefoot being the same softness.

There’s prominent forefoot rocker on the Max to assist with transitions. It also has a stiffer forefoot than the 21. The 21 has a more natural ride and has a more flexible forefoot because its midsole is thinner.

Stability is better in the 21 because your feet sit lower to the ground. Its firmer ride also translates to less lean bias so it offers more support than the Max.

On the outsoles, the 21 has more rubber than the Max. This gives it better outsole durability and more midsole foam protection from the road.

Both of these trainers have extremely comfortable uppers which feel luxurious. The main difference is that the material of the Glycerin Max is a traditional mesh whereas the Glycerin 21 material feels more like a knitted material.

The Max has better breathability because it has holes on the top of the toe box for ventilation. It also has a thinner upper than the one on the Glycerin 21.

They both fit true to size but have narrow fitting uppers. The Glycerin 21 is available in a wide version while the Max is only available in a standard width.

If you want the softest, plushest ride for easy/recovery runs, you should get the Glycerin Max. It has deeper cushioning and it has more long-distance comfort so it’s the better shoe for doing long runs in. It has a rocker which assists you through transitions and it has a cooler upper.

If you want a more balanced ride which can handle faster paces better, you should get the Glycerin 21. It’s a little bit lighter and it has more stability. It has a more natural ride with more ground feel and it has better outsole durability. If you have wide feet, the wide version of the 21 will be more comfortable for you. It also costs $40 less than the Max.