Brooks Beast 20 VS Glycerin 21: What Should I Buy?

Running shoes are an important investment for runners. With so many options on the market, it can be tough to decide which shoe is the best fit for your needs. Two popular stability running shoes from Brooks are the Beast 20 and the Glycerin 21. But how do you choose between them?

This in-depth comparison examines the key features of the Brooks Beast 20 and Brooks Glycerin 21 to help you determine which shoe is better for your running style and preferences. Read on for a breakdown of sizing, weight, materials, performance, and more.

Similarities And Differences Between Brooks Beast 20 And Glycerin 21:

FeatureBeast 20Glycerin 21
Launched In20202024
StabilityMediumSupportive and stable
FlexibilityModerateModerately flexible
SizingMen’s 7-18, EEE widthWomen’s 5-12Men’s 7-17Women’s 5-12
Weight11.2 oz (men)10.2 oz (women)9.30-10.50 oz
CushioningPlush and softPlush and comfortable
OutsoleSegmented rubberDurable rubber
MidsoleDNA Loft v3DNA Loft
UpperEngineered meshEngineered mesh
Retail Price$160$160

Features Comparison:


The Beast 20 uses a breathable engineered mesh upper to provide a flexible, sock-like fit. The Glycerin 21 also utilizes an engineered mesh upper for ventilation and stretch.

Brooks Beast 20


Underfoot, the Beast 20 incorporates a DNA Loft v3 midsole while the Glycerin 21 uses the DNA Loft cushioning. Both shoes have a rubber outsole, but the Beast 20’s outsole is segmented for flexibility.


The Beast 20 displays improved durability over past Beast models, with testers reporting the shoe lasts for 300-500 miles before signs of midsole breakdown. The segmented rubber outsole resists abrasion and the DNA Loft v3 foam maintains cushioning even at high mileages.

Similarly, the Glycerin 21 is praised for its longevity thanks to a sturdy rubber outsole and DNA Loft midsole that withstands heavy mileage without losing bounce or traction. Both shoes are crafted with quality materials that promote durability for the long haul.


The Beast 20 runs true to size for most, but some may size up a half for a roomier toe box. Wide feet benefit from the 4E width available for men. The engineered mesh upper provides a flexible, sock-like fit.

Brooks Beast 20 Top View


In contrast, the Glycerin 21 fits snugger in the midfoot and heel with less give in the upper. The midfoot cage locks in the foot. Going up a half-size gives more wiggle room. The Glycerin 21 better suits narrow to medium feet, while the Beast 20 accommodates wider feet and high-volume sizes.


The Beast 20 delivers ultra-plush cushioning through its thick DNA Loft v3 midsole which provides a soft, pillowy ride. This proprietary foam runs the length of the shoe to absorb shock and protect joints. Testers describe the marshmallow-like feel underfoot.

In contrast, the Glycerin 21 utilizes a DNA Loft midsole that balances cushioning with responsiveness. There’s enough padding for comfort and shock absorption over long distances, but the ride feels closer to the ground compared to the maximum softness of the Beast 20. The Glycerin 21 offers a plush, comfortable feel without being overly cushy.


With a $140 price tag, the Beast 20 costs $20 less than the Glycerin 21 at $160. Considering its plush DNA Loft cushioning, GuideRails support, and traction outsole, testers felt the Beast 20 provided excellent value for stability shoes. The long durability also adds value.

While priced higher, the Glycerin 21 is still considered reasonably priced for premium running shoes. Testers thought the DNA Loft midsole, engineered mesh upper, and rubber outsole made the Glycerin 21 a worthwhile investment for its versatile performance across different running paces and distances. Overall, both models deliver great features at moderate price points.

Performance Comparison:


The Beast 20 provides responsive cushioning and support for walking, with testers commenting on the “pillowy soft” feel underfoot. The roomy toe box allows a natural stride. However, some may find it slightly heavy.

With its flexible sole and comfortable upper, the Glycerin 21 is also a solid choice for walkers seeking a stable and smooth ride. It’s decently lightweight for a support shoe.


Ideal for recovery runs and longer distances, the Beast 20 offers plush, stable cushioning that holds up to higher mileage. The grippy outsole also delivers traction on varied terrain.

As a more nimble, medium-cushioned option, the Glycerin 21 works well for moderate-pace runs up to a half marathon. The responsive midsole provides a smooth transition.

Plantar Fasciitis:

The Beast 20 provides ample cushioning and arch support to relieve plantar fasciitis pain. The soft midsole absorbs shock while the stability features keep the foot properly aligned.

With its soft DNA Loft foam, the Glycerin 21 also eases pressure on the plantar fascia. However, it may not offer enough arch support for some.

Standing All Day:

Nurses, retail workers, and others on their feet all day need a supportive shoe with cushioning to absorb shock. With its plush midsole and comfortable upper, the Beast 20 is a top pick for standing for long hours.

While reasonably cushioned, the Glycerin 21 has less padding than the Beast 20, especially in the rearfoot. Thus, the Beast may reduce fatigue better for all-day wear.

Final Verdict:

In summary, the Beast 20 stands out for its ultra-cushioned yet supportive ride that comforts overpronators across different activities. It offers excellent shock absorption and stability for running, walking, plantar fasciitis, and standing all day. The spacious fit works well for wide feet.

The Glycerin 21 provides a medium-cushioned, flexible fit in a lightweight package. It works great as a daily trainer for moderate-pace runs up to half marathon distances. While decently stable, it does not control overpronation as well as the Beast.

Overall, runners needing maximum stability and cushion should opt for the Beast 20. But if you desire a more responsive, nimble feel, the Glycerin 21 takes the lead. Consider your arch type, mileage needs, and intended uses to decide which of these Brooks trainers is better for you.

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