If you’re a neutral runner searching for a comfortable, well-cushioned shoe that can go the distance, the Brooks Glycerin series should be on your radar. The Glycerin 20 and 21 are both premium neutral shoes designed for high mileage, but they have some key differences.
Read on for an in-depth comparison of these two popular models to help you decide which version of this beloved shoe is the better fit for your needs.
Similarities And Differences Between Glycerin 20 And 21:
| Feature | Glycerin 20 | Glycerin 21 |
|---|---|---|
| Launched In | 2022 | 2024 |
| Stability | Neutral | Neutral |
| Flexibility | Moderate | Moderate |
| Sizing | Men’s 7-18, Women’s 5-13 | Men’s 7-18, Women’s 5-13 |
| Weight | 10.9 oz (M), 9.2 oz (W) | 9.30-10.50 oz |
| Cushion | Plush | Plush |
| Outsole | Segmented rubber | Segmented rubber |
| Midsole | DNA Loft v3 | DNA Loft v3 |
| Upper | Engineered mesh | Engineered mesh |
| Retail Price | $160 | $160 |
Features Comparison:
Materials: Outsole, Midsole, Upper:
The outsole and midsole materials are identical in the Glycerin 20 and 21. Both feature rubber segmented outsoles for durability and grip. The star of the show is the DNA Loft cushioning in the midsole, providing plush softness without losing responsiveness or durability.
The stretchy engineered mesh upper is also the same in both versions, optimizing breathability. Overall, there are no differences in materials between models.
Durability:
With beefy rubber outsoles and Brooks’ long-lasting DNA Loft foam, both the 20 and 21 earn high marks for durability and longevity. However, the Glycerin 21 shaves off a tiny bit of weight, dropping from 10.9oz to 10.7oz for men and 9.2oz to 9.0oz for women. The slightly lighter 21 may have a slight edge in retaining midsole cushioning over many miles.
Fit:
The engineered mesh upper offers a comfortable, secure fit in both Glycerin versions. Sizing is identical, with average width options accommodating most foot shapes. Overall, you can expect the same great fit feel in the 20 and 21.
One difference is that testers note the Glycerin 21 runs slightly warmer than the well-ventilated 20. For hot weather, the 20 may fit more breezily.
Stability:
As neutral shoes, neither model offers pronation correction or guidance. Both are cushioned and supportive but better for neutral gaits, not over- or under-pronation. Stability is on par between the two.
Cushioning:
Delivering on Brooks’ reputation for soft landings, both 20 and 21 feature the same DNA Loft cushioning technology spanning the full length of the midsole. Responsiveness does not suffer, while impact protection shines in both models. If a pillow-soft ride is your top priority, it’s a wash here.
Value for Money:
With the exact same $160 price tag and nearly identical builds, the Glycerin 20 and 21 deliver strong value. The 21 makes tiny performance tweaks like weight reduction and possible improvements to breathability.
But the tried-and-true Glycerin 20 design still brings lots of cushion and comfort per dollar spent. Overall value is stellar in both versions.
Performance comparison:
Walking:
As high-mileage neutral trainers, both models perform well for walking. The plush midsole and supportive fit make spending the day on your feet comfortable in both versions. The Glycerin 21’s lighter weight gives it a slight edge for all-day wear, but casual walkers would be happy in either pair.
Running:
While hefty for racing, these shoes shine for long-distance comfort. The Glycerin DNA Loft cushioning ensures your joints stay happy mile after mile. The 21 improves slightly on weight, but both earn glowing reviews as marathon companions. Glycerin fans flock to the line for its run-saving softness.
Plantar Fasciitis:
Cushioned, supportive shoes are a must for plantar fasciitis. With max-softness DNA Loft foam, the Glycerin series offers the gentle landing PF sufferers need. Those with chronic heel pain praise the heel counter support too. For sore feet, either model works wonders thanks to premium impact protection.
Standing All Day:
Even without specialized technology for all-day wear, both neutral Glycerins transition well for long hours on your feet. Testers experience less back and joint pain thanks to responsive DNA Loft cushioning. The 21’s lighter weight gives it an advantage for fatigue reduction over extended shifts. But neither disappoints as an everyday station shoe.
Final Verdict:
For most runners, the Glycerin 21 makes small but meaningful improvements over an already beloved shoe. A little weight trimmed, a little more breathability eked out. But both remain classic distance shoes packed with pillowy DNA Loft comfort.
If you found a perfect fit in the Glycerin 20, stick with it. But for new buyers or those with hot feet or sore joints, the Glycerin 21 optimizes an outstanding formula. For optimal lightweight comfort across long miles, the Glycerin 21 stands as today’s top choice.