They say ‘nothing new on race day’…
I have always subscribed to that theory until I was able to get my feet in the new Brooks Glycerin 21.
My risk paid off as I rounded the warning track of MGM Park to the finish line for a new marathon PR and feet that did not hate me. But does one day of fortune equal a home run for arguably the running community’s most popular shoe brand? Let’s find out!
The Glycerin is Brooks’s premium max cushioned daily trainer.
The new Glycerin 21 comes in 4 offerings: Glycerin 21, Glycerin 21 GTS, Glycerin 21 StealthFit, and Glycerin 21 StealthFit GTS. Brooks’ flat knit upper, Stealthfit, is designed to hug the foot. GTS stands for ‘go to support,’ and is the shoe’s stability version, with guide rails on both sides of the upper. I put just shy of 100 miles in the Glycerin 21 StealthFit.
Specs (Glycerin 21 Stealthfit)
- Weight: W 8.3oz M 9.3 oz
- Stack Height: 38mm/28mm
- Drop: 10 mm
- Surface: Road
- Category: Neutral Daily Trainer
- Fit: True to size
- Price: $160
What’s New
- Added 2mm foam
- Updated ‘StealthFit’ one piece upper
- Widened platform
- More pronounced rocker
- Decoupled outsole
- ‘RoadTack’ Rubber
Upper
For 2023, the Glycerin 21 StealthFit received an updated flat knit upper. The one piece upper is designed to hug the foot like a sock, adding compression and the ability to move with your foot. The heel counter is flexible with added cushioning around the ankle and achilles. The tongue comes up higher on the foot than a traditional tongue with a loop for putting on the shoe. Brooks utilizes a flat shoe lace in an external lacing system.
MIDSOLE
The Glycerin 21’s midsole is made of Brooks’ proprietary DNA Loft foam, a combination of EVA foam, rubber, and air. The midsole benefits from the injection of nitrogen, resulting in the third version of the foam, DNA Loft V3. This will be the last year of the V3 foam with a new iteration coming the next model year. Aside from the Aurora BL, the Glycerin 21 is currently the only shoe in the Brooks lineup that uses DNA Loft V3 foam. An extra 2mm of stack height adds cushioning to an already well-cushioned shoe. An updated wider platform adds stability to the shoe.
MIDSOLE
The Glycerin 21’s midsole is made of Brooks’ proprietary DNA Loft foam, a combination of EVA foam, rubber, and air. The midsole benefits from the injection of nitrogen, resulting in the third version of the foam, DNA Loft V3. This will be the last year of the V3 foam with a new iteration coming the next model year. Aside from the Aurora BL, the Glycerin 21 is currently the only shoe in the Brooks lineup that uses DNA Loft V3 foam. An extra 2mm of stack height adds cushioning to an already well-cushioned shoe. An updated wider platform adds stability to the shoe.
OUTSOLE
The ‘RoadTack’ outsole, made of rubber and recycled silica, is new for the Glycerin 21. The introduction of recycled silica has helped reduce the overall weight of the shoe. The outsole is now decoupled allowing the foam to expand more freely below the foot.
PROS
- Zone 2 effort runs were effortless in the Glycerin 21. The DNA Loft V3 foam hits that ‘Goldilocks’ combination of softness and firmness. The updated rockered geometry of the shoe provides smooth transitions through each stride.
- I was able to get a good lockdown with the stealtfit upper. I found it comfortable throughout my marathon and attributed that to the ability of the knit to expand with my foot as I got further into the race.
- The 'RoadTack' outsole is grippy and works well on wet surfaces. After nearly 100 miles, the outsole shows little wear.
- This is a durable shoe. I expect most runners to get 500 miles out of the Glycerin 21 before the midsole bottoms out and the outsole wears away.
CONS
- An uptempo shoe this is not. I struggled to get good leg turnover in this shoe at tempo and threshold efforts.
- The light feel of the StealthFit upper combined with the chunky midsole felt awkward at 10k race pace and faster.
- While there is added cushioning, the StealthFit upper does not give much support for the ankles. If you have weaker ankles then I would opt for the more traditional warp knit upper.
is this shoe for you?
The Glycerin 21 is a great choice for anyone looking for a max cushioned daily trainer or easy day, long run shoe that possesses a nice balance of cushioning and firmness in the midsole.
It also makes a great shoe for first time marathoners that plan on spending 4+ hours on their feet or a road ultra marathon. The 10 mm drop and stability provided by the wide base will cater to most runners.
WRAP UP
The Brooks Glycerin 21 is a max cushioned running shoe featuring the latest in DNA Loft technology and ‘RoadTack’ outsole. A ‘do it most’ shoe that struggled at uptempo efforts but excels at daily and easy paces, with the capability to go the distance on race day. The four versions offer a fit for a full array of runner preferences.
The Brooks Glycerin 21 and Glycerin 21 GTS will be available 1/10/24 at Run N Tri Mobile. Aaron and staff provide a premier fitting process that includes proper measurement of the length and width of your feet, arch, and leg axis. A gait analysis is performed to identify pronation or lack thereof and pressure points. In addition, an interview is conducted to determine the best type of shoe for your needs and goals.
So stop by Run N Tri Mobile so they can put you in the latest max cushioned offering from Brooks or one of the nine other brands carried in the shop.
