Brooks

Brooks Glycerin 21

The Brooks Glycerin 21 is a premium max-cushion daily trainer positioned at the top of Brooks' neutral running shoe lineup.

### Overview

The Brooks Glycerin 21 is Brooks' most cushioned everyday training shoe, built around a deeply comfortable, smooth ride for easy and long-distance miles. Two more millimeters of DNA LOFT v3 foam underfoot, a brand new upper, and a solid coat of Brooks' new RoadTack rubber make up the key updates of the 21st version. It's a workhorse training shoe designed to log high amounts of miles in.

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### Standout Features

- **DNA Loft v3 Cushioning:** The midsole is made of Brooks' proprietary DNA Loft foam — a combination of EVA foam, rubber, and air — enhanced by nitrogen injection to produce the third-generation v3 formula. - **Generous Stack Height:** Stack heights measure 38 mm at the heel and 28 mm at the forefoot, with a softer, more cushioned ride than its predecessor due to 2 mm of extra stack height. - **Engineered Air Mesh Upper:** The engineered warp knit upper offers a very accommodating, comfortable fit, with a construction that stretches more and conforms to your feet better than the traditional mesh upper of the Glycerin 20. - **GuideRails Support (GTS variant):** The Glycerin 21 is available in both a neutral version and a version that offers a mild amount of anti-pronation support — the Glycerin GTS 21. Thanks to the GuideRails, the heel feels slightly firmer, adding stability without overcorrecting your stride. - **RoadTack Outsole:** The shoe gets a new RoadTack outsole made of rubber and recycled silica, offering great traction in all weather conditions — and you can expect to get close to 500 miles from the pair. - **10 mm Heel Drop:** The 10 mm drop is standard for Brooks, giving your foot a slight forward tilt that helps reduce pressure on the Achilles tendon.

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### Who It's For

The Glycerin 21 is recommended for use as a daily cruiser and for half-marathons and marathons. It's particularly suitable for heel strikers, providing a stable ride that excels on long runs. If you're a heavier runner or prefer your max-cushioned trainers to be stable rather than super soft, the Glycerin 21 is a strong option.

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### Important Considerations

- **Not built for speed:** The Glycerin 21 doesn't like to be pushed hard — it's on its best behavior at speeds slower than 8:00 min/mile. - **Warmth:** It may be too warm for hot summer runs, so runners in consistently hot climates may want to consider a more breathable alternative. - **Fit note:** Brooks retained its usual tapered toebox design, and a measured width of 71.7 mm confirms a narrower fit that may pose a challenge for those with square-shaped feet. - **Pricing:** Priced at $159.95, some reviewers note it feels behind from a materials standpoint compared to competitors at a similar price point.

Key features

• DNA Loft v3 cushioning
• engineered air mesh
• GuideRails support

Seen at 3 retailers from $110.93 to $160.00 as of 2026-06-14. Prices change — check the retailer for the current price.

DNA Loft v3 cushioning delivers a plush, consistent ride that holds up across long miles without feeling spongy.