Brooks Glycerin 20 vs 21: Is the Upgrade Worth it?

New running shoe releases often spark debates among serious runners. Some changes transform how we run, while others make athletes question the need to upgrade. The Brooks Glycerin series now faces this challenge with its latest model.

The Brooks Glycerin 21 follows the successful Glycerin 20 with promises of improved comfort and better performance features. Let's get into the key differences between the Brooks Glycerin 20 vs 21. This comparison will help you decide if the new version belongs in your running gear.

What's New in the Glycerin 21?

Brooks has made the Glycerin 21 better than ever with state-of-the-art features that make it stand out from the Glycerin 20. The DNA LOFT v3 cushioning system now has an extra 2mm of cushioning material compared to its predecessor. This makes it Brooks' most cushioned running shoe yet.

The shoe comes packed with advanced technology:

• A new RoadTack rubber outsole with recycled silica boosts durability
• The engineered warp knit upper gives better structure and security
• A wider platform design adds stability
• Better flex groove placement helps adapt to ground impact

The Glycerin 21's design looks more polished with smart color choices. The shoe's different zones pop through clever color placement that shows off the landing zone, mid-zone, and toe-off sections of the midsole. The switch from air-mesh to warp knit technology keeps the shoe breathable and adds support where needed.

The shoe's weight tells an impressive story. The men's version weighs 278g - lighter than the previous 286g. The women's model follows suit at 258g, weighing less than before. Brooks achieved these weight cuts even with extra cushioning by using materials smartly and redesigning the RoadTack rubber layout.

The Glycerin 21 sits in the premium running shoe category with a £165 price tag. Serious runners will find value in its longer-lasting RoadTack rubber, extra cushioning, and improved design. Brooks backs the shoe with a 90-day trial run guarantee, which gives buyers peace of mind when upgrading.

Performance Deep Dive

Road tests reveal the Brooks Glycerin 21's true performance character. This shoe shows impressive versatility in running conditions of all types. Its DNA LOFT v3 cushioning measures 20.4 HA in softness tests, suggesting an ideal mix of comfort and stability.

Road testing experience

The Glycerin 21 excels in long-distance runs where runners benefit from the extra 2mm stack height. The new RoadTack rubber delivers reliable traction in wet conditions. Flexibility tests show the shoe needs just 21.7N of force, which makes it adapt well to different running styles.

Comfort and cushioning analysis

The nitrogen-infused DNA LOFT v3 midsole feels noticeably different from its previous version. This comfort-focused trainer's cushioning responds better while staying plush. A broad platform design has boosted stability, which helps during heel-to-toe transitions.

Key comfort features include:

• Better shock absorption from the deeper midsole
• Balanced support for high arches
• Smooth heel-to-toe transition mechanics

Energy return and responsiveness

The Glycerin 21 shows laudable energy return characteristics despite not being built for speed. Daily training gets enough bounce from the nitrogen-infused midsole, though it stays true to its comfort-first identity rather than focusing on speed. Tests show the shoe runs warmer than average, which means it performs best in cooler conditions.

Recovery runs and longer training sessions showcase this shoe's strengths, where its improved cushioning makes the biggest difference. Runners will appreciate the perfect balance of comfort and responsiveness most at easy to moderate paces.

Fit and Feel Comparison

Brooks made big updates to improve the Glycerin's comfort and design. The shoe now uses warp knit technology instead of air-mesh, which marks a major step forward in its construction.

Upper comfort and breathability

The Glycerin 21 features a new engineered warp knit upper that feels luxurious and stays structurally sound. The thicker knit construction has 11.5mm of tongue padding, making it run a bit warmer than the last model. The shoe breathes well enough in most conditions, but runners might feel extra warmth during hot weather runs.

The shoe shines with these comfort features:

• A silky-soft heel collar packed with improved memory foam
• A plush tongue that prevents lace pressure
• A flexible midfoot wrap that locks your foot in place

Sizing and width options

Brooks suggests going 1/2 to one size up from your dress shoe size to get the best fit. The Glycerin 21's toe box gives you more room than the previous model, measuring 99.3mm at its widest point. You can choose between classic fit and StealthFit options that work well for different foot shapes.

Break-in period differences

The Glycerin 21's most important upgrade is how comfortable it feels right away. The previous model needed several runs to feel right, but the 21 gives you consistent cushioning from day one. The forefoot stays somewhat stiff at first and needs about 30 miles of running to reach its full flexibility.

Who Should Choose Each Model

Your choice between Brooks Glycerin models really comes down to your running priorities and training goals. A good look at what makes each version unique will help you pick the right shoe.

Ideal runner profiles

The Glycerin 21 works best for:

• Heel strikers who need maximum cushioning during marathon training
• Runners who need lasting shoes for high-mileage training
• Neutral runners searching for a cushioned daily trainer
• Ghost series fans who want extra cushioning

The knit upper doesn't breathe well in warm weather, so you might want to look at other options if you run in hot or humid places.

Training specific recommendations

The Glycerin 21 shines at speeds slower than 5:00 min/km (8:00 min/mile). This makes it a great pick for daily training and long-distance runs. Marathon runners aiming to finish beyond 3:45 will find these shoes perfect. These shoes are exceptional for recovery runs and help runners keep good form during easier training sessions.

Transition considerations

The Glycerin 21 packs 2mm more cushioning than the previous model. Runners who need extra support can pick the GTS version with GuideRails® technology that helps protect your knees on longer runs.

Lighter runners with neutral gait patterns will do fine with the standard version. Heavier runners might notice the midsole compressing more. The 10mm heel-to-toe drop works great for heel strikers, and midfoot strikers can still transition smoothly.

Brooks' Run Happy Promise gives you 90 days to try these shoes. This gives you plenty of time to get the full picture before upgrading.

Conclusion

The Brooks Glycerin 21 shows real progress from its earlier version with notable improvements in cushioning, durability, and performance. Its DNA LOFT v3 cushioning system and new RoadTack rubber outsole work together to create a shoe that handles daily training and long-distance runs effectively.

The shoe adds 2mm of cushioning and better stability features - perfect for runners who pile on the miles. The warp knit upper feels a bit warmer than the Glycerin 20's. However, most runners find the improved structural support and better fit worth this small compromise.

Your choice between Glycerin 20 and 21 comes down to what matters most to you. The Glycerin 21's updates make sense for runners who want a comfort-first experience and log many weekly miles. This shoe shines during recovery runs and long-distance training sessions, making it ideal for runners who care more about cushioning than speed.