Brooks’s marketing pitch: Supremely soft, mile after mile.
Upper: Engineered mesh, high-density printing, no sleeve.
Midsole: Full-length Nitrogen-infused EVA foam. 10 mm heel drop.
Outsole: Carbon rubber.
Weight: 292 gms/ 10.3 Oz for a half pair of Men's US 9/UK 8/EUR 42.5/CM 27
Widths available: D - regular (reviewed), 2E - wide.
Previous model: Brooks Glycerin 19.
Country of origin: Made in Vietnam.
In this review:
Only Brooks can do this.
They redesigned their top-tier cushioning trainer with a brand new DNA Loft V3 midsole to create a shoe that’s not softer, quicker, or lighter than the previous version. The price even went up by $10, from $150 to $160.
Brooks advertises the Glycerin 20 as ‘supremely soft’, but that claim contradicts with the on-road behavior. To Brook’s credit, the DNA Loft V3 is softer than what’s on the Glycerin 19, but the on-road cushioning softness isn’t just about the foam.
The new midsole uses DNA Loft V3, which appears to be an EVA foam blend that uses Nitrogen as a blowing agent.
By the way, this foam was first used on the Brooks Aurora BL, a running shoe that had the appearance of misshaped marshmallows clumped together.
At running speeds, the new Glycerin has a firmer ride than the Glycerin 19. Not all of the firmness is due to the new foam. Since DNA Loft 3 is softer, the midsole geometry plays a greater role in the ride quality. More on that in a bit.
The Glycerin 20’s weight is identical to the outgoing Glycerin 19, as both shoes tip the scale at just over 10 ounces for the median size. The Glycerin 20 is equal to the Glycerin 19 in most performance areas, so its core character hasn’t changed.
If you don’t know what that means, the Glycerin 20 continues to be a comfortable and supportive neutral trainer for long-distance runs at easy paces. The Goldilocks zone for the Glycerin 20 would be in the 5:30 min/km (8.50 min/mile) pace.
The Glycerin 20 is a 10.2-ounce shoe, so it’s not lightweight. The 10 mm heel offset midsole lacks a beveled landing zone, so rearfoot strikers would be in a relatively better position to benefit from the Glycerin 20.
In our opinion, the Glycerin 20 doesn’t offer a compelling reason to upgrade from the Glycerin 19.
The Glycerin 20 has better stability, that’s all. Otherwise, the Glycerin 19 outperforms the 20 in most performance areas, including the quality of transitions. Unless you intend to use the Glycerin 20 as a walking shoe – in that case, the DNA Loft V3 has a softer ride of the two.
THE BROOKS GLYCERIN 20 COMPARED WITH GLYCERIN 19
As a running shoe, the Glycerin 20 has a firmer ride than the Glycerin 19. That’s saying something, because even the Glycerin 19 didn’t have a particularly soft ride.
We’d like to clarify that this observation applies during running speeds. At walking speeds, the DNA Loft V3 midsole feels softer due to the longer loading time.
However, during runs, the Nitrogen-infused DNA Loft V3 feels firmer than the 19. That’s because the new foam is more resilient and has better feedback than the previous DNA Loft foam. The Glycerin 20’s midsole foam is quick to return to its original position, and doesn’t shear as much. That translates into a higher level of firmness.
There’s another reason why the ride is firmer.
All Glycerin models till the 19 had a groove on the outer midsole that compressed when loaded; that added to the cushioning softness. The Glycerin 20 no longer has the groove. Ok, though a faint outline of a groove exists, it does not affect the midsole softness.
Also, a couple of changes make the Glycerin 20’s forefoot stiffer than the 19.
The first update would be the thicker Loft V3 foam. The second factor is the redesigned flex groove that is aligned lengthwise instead of the Glycerin 19’s side-to-side orientation. These updates make the Glycerin 20’s forefoot harder to bend.
For the first time since we began reviewing the Glycerin, the tongue doesn’t have an internal gusset. Other than that, the interiors are plush and secure as ever. The new upper has a slightly narrower fit than the previous version, particularly over the small toe area.
THE MIDSOLE DESIGN AND RIDE EXPERIENCE
Brooks should stop calling the Glycerin super soft, because it’s not. The Nike ZoomX Invincible is super soft. The New Balance Super Comp trainer and Hoka Bondi 8 can also be described as super soft.
It’s like New Balance calling its original Fresh Foam 980 ‘science of soft’, when in reality, the 980 was a firm shoe with a soft insole.
The G-20 is a medium-soft running shoe that borders on a firm. It has a decent layer of step-in softness, courtesy of the removable insole and foam lasting.
So what about the bounciness? Is the DNA Loft V3 anything like Saucony’s Pwrrun PB or Nike ZoomX foam? Not quite; while there is a trace of responsiveness, most runners won’t experience it during a run.
Historically speaking, the Glycerin has always been a running shoe with a firm ride, so why is Brooks so insecure about midsole softness?
Solereview’s first encounter was with the Glycerin 9 over a decade ago, and even back then, it combined upper plushness with a relatively firm midsole.
Coming to think of it, the original ‘DNA’ tech was a non-Newtonian Gel that turned into a firmer cushioning material during landings. It was a replacement for the Brooks Hydroflow, another Gel-based cushioning that competed with the Asics Gel.
In 2015, Brooks quietly updated their DNA Gel cushioning with an all-foam midsole, and the name kind of stuck.
Over the years, the term DNA has had its share of prefixes and suffixes. Like Super DNA, BioMogo DNA, DNA Loft, and so on. We’re willing to bet that even Brooks has forgotten what DNA was about.
In essence, the Glycerin 20 has traces of the Glycerin 9’s ride behavior. The Gel-based Glycerin 9 felt softer at walking speeds and standing, but firmed up during runs.
Therefore, how the Glycerin 20 feels during a fitting session at your local store isn’t an accurate representation of how the shoe feels at running speeds.
So if the DNA Loft V3 is a softer compound, why does the Glycerin 20 feel firmer once you pick up speed?
The Glycerin 19’s midsole has a slimmer base just under the upper before it flares out wide. There’s also a compression groove that allows the rear midsole to flex and splay during footstrike and transitions.
It’s also worth mentioning that the resilient DNA Loft V3 is more resistant to flexing, so the Glycerin 20’s midsole doesn’t benefit from the compression groove that the Glycerin 19. As we said, this is only noticeable at running speeds – say faster than 5:00 min/km (8 min/mile) level runs.
When standing or walking, the Glycerin 20 is the softer of the two. The longer weight loading time allows the wide and deeply-cushioned DNA Loft v3 midsole to compress – and that results in a higher level of sensory softness.
We hope this makes sense.
At a conceptual level, the DNA Loft V3 is very similar to the DNA Flash foam of the Hyperion Tempo. It’s firm, resilient, and exhibits a similar road behavior.
On the flip side, the Glycerin 20 is a heavy running shoe. It weighs 10.3-ounces (292 grams) for the median size, and our US 11 shoe weighed 11.3-ounces for a half pair. In other words, the new foam doesn’t result in weight savings.
In real-world terms, that means that the Glycerin 20, just like the Glycerin 19, has limited versatility. That’s not a bad thing, since most running shoes do well in one area. For the Glycerin, it shines as a cushioned and stable neutral trainer for long and easy-paced runs.
This isn’t a shoe that feels comfortable going quicker than 5:30 min/km (8:50 min/mile), so it’s best reserved for long-distance cruising or daily runs at unhurried paces. You can go fast in the Glycerin 20, but the experience feels like a boring chore.
One would assume that the firm ride and stiffer forefoot make quick transitions happen, but the overall bulk gets in the way.
While we’re discussing the forefoot, it’s worth underscoring that the re-oriented flex grooves and firmer foam make the shoe more resistant to flexing. The grooves no longer span sideways, but length-wise.
The ride stability is a significant improvement. The firmer DNA Loft V3 is more resistant to compression than the previous model, and certain changes in the midsole design also make the Glycerin 20 more supportive.
Keep in mind, though, that while the overall stability is excellent, that doesn’t necessarily translate into a higher level of under-arch support.
The midsole lacks a flare like how the Saucony Ride and Guide 15 do, so there is no arch support – at least from a sensory perspective. The GTS version of the Glycerin fares slightly better in that regard, but those raised sidewalls aren’t perfect.
A glance at the midsole reveals the ‘bumpy’ sidewall profile. These molded bumps create a wide midsole base under the heel and forefoot.
The midsole also lacks a deep compression groove on the outer midsole, so the Glycerin 20’s behavior is more neutral than the 19.
The transition groove under the midsole also helps maintain straight-line tracking during the gait cycle.
Its impact on the cushioning softness is negligible, but it plays a role in keeping the weight centered. The outsole rubbers nearly all of the midsole without any awkward gaps in the transition path.
If you’re a heavy runner looking for a reliable daily trainer, the Glycerin 20 is a very strong contender. A few years ago, we said the same thing of the Brooks Levitate – another running shoe with a firm and supportive ride.
An ideal three-shoe rotation from Brooks would comprise the Hyperion Elite 3 for marathons, the Glycerin 20 for long and easy runs, and Hyperion Tempo for, well, tempo runs and races.
But that’s a lot of money to spend on shoes, so may we suggest shoes from other brands?
The Saucony Endorphin Speed V2 makes for an excellent marathon racer, and costs far less than the Hyperion Elite. The Endorphin Speed V2 has an s-curved Nylon plate for that signature snap, whereas the PEBA core keeps the long miles comfortable. Read our review of the Endorphin Speed V1, because it has an identical ride character.
There are many racing shoe options, but we like the adidas adios 6 (now V7) the best. It’s aggressive enough to be a road racer, yet cushioned enough to be a tempo trainer for speed runs.
IS THE BROOKS GLYCERIN 20 DURABLE?
This new midsole material hasn’t been in the market (the Aurora BL doesn’t count) for long, so its durability is just an educated guess. If our initial testing is anything to go by, we think that the DNA Loft V3 will last as long as the foam on the Glycerin 19.
In mileage terms, that’s approximate 400 miles. This estimate includes the slow wear and tear of the outsole, as well as the foam insole and lasting.
In the past, the Glycerin’s upper has never had durability-related concerns, and we believe that’s also going to hold for the Glycerin 20.
THE UPPER DESIGN AND FIT
The Glycerin 20’s upper fit is very similar to the 19, except for one missing ingredient. The tongue is no longer attached to an inner gusset or saddle. This is a surprise; the Glycerin has always had a sleeve regardless of the year.
What was more surprising though, is that the tongue doesn’t slide as much as expected. The flat laces do a good job of keeping the tongue secured over the foot, at least on runs up to a 10K.
In the past, Brooks had a nifty little feature called the ‘tongue tied’ loop that prevented the tongue from sliding on non-gusseted uppers. Maybe it’s time for the tongue loop to make a triumphant return.
Except for the inner gusset, the Glycerin 20 has a similar fit as the 19. It does feel slightly tighter over the small toe, but the rest of the upper feels familiar.
If you’re a wide-footed runner, getting the 2E width wouldn’t be a bad idea.
The interior has a true-to-size fit with plenty of plushness packed within. The tongue and heel use a soft lining for a comfortable grip, and the stiff internal counter also locks the foot in. The quilted tongue filters all the lacing pressure.
The ventilation levels are average – it’s not overly breathable or stuffy. In short, the Glycerin 20 has an all-season upper – except for rainy days, that is.
Reflectivity is absent on the upper. Its omission is surprising on a $160 shoe that doesn’t skimp on other cosmetic details like the high-density printing and decorative padding on the outer heel. There are small metallic trims on the toe-box and heel, but they are ineffective in low-light conditions.
Before we wrap up this section, a brief digression on the ‘Stealthfit’ variants of the Glycerin 20 is merited.
Brooks sells the Glycerin 20 Stealthfit, a version with a partially stretchy upper. The entire upper isn’t elastic, only the top of the tongue is. The forefoot has a bit of a stretch, but not like the adidas Primeknit from the Ultraboost.
Though the Stealthfit model has a (more) conforming fit than the standard upper, we found the positioning of its collar padding odd.
It’s much lower than the regular Glycerin 20, so the top of the heel doesn’t have an impact role on the heel grip. The foot-hugging upper will also run warmer than the engineered mesh version.
The heel doesn’t slip, but the low position of the padding takes some time to get used to. The Glycerin 20 Stealthfit also feels bottom-heavy as compared to the regular Glycerin 20 due to the lighter weight. The knit upper results in a weight savings of 0.8-ounces or 23 grams.
PROS AND CONS
Regardless of the new midsole foam, the Glycerin 20 maintains its Glycerin-ness. So the list of pros and cons is similar to the last Glycerin and the versions that came before it.
Though Loft V3 isn’t as soft as Brooks describes it to be, the firm and wide midsole offer excellent stability. The ride comfort also isn’t lacking – except that it’s not a ‘supremely soft’ kind.
While the Glycerin 20 may be a good shoe for everyday runs at easy speeds, its versatility is limited by its bulk – this shoe weighs over 10 ounces.
The upper uses premium trims to create a plush interior, and the fit is true to size. Additional widths are available too. However, we have no idea why Brooks got rid of the internal gusset.
For all practical purposes, reflectivity is non-existent.
COMPARISON: THE BROOKS GLYCERIN 20 VERSUS BROOKS GHOST 14
At the time of publishing the review, the Brooks Ghost 15 hasn’t been released yet. Based on internet chatter, the Ghost 15 is similar to the 14, as it uses the same midsole material. If that’s true, then a comparison between the Glycerin 20 and the current Ghost 14 is relevant.
The Ghost 14 is slightly lighter than the Glycerin 20 and is $20 cheaper. From a performance point of view, the Ghost 14 is more versatile. In short, it’s a better everyday trainer than the Glycerin 20 since it feels relatively more agile at speeds faster than 5:30 min/km (8:50 min/mile).
The Ghost 14 has a lighter and thinner mesh exterior than the Glycerin, so it breathes better.
SHOES SIMILAR TO THE BROOKS GLYCERIN 20
Before diving into the list of alternatives, it’s worth summing up what the Glycerin 20 is about. It’s a comfortable yet supportive neutral trainer with a 10 mm drop, and its weight limits it to slower distance runs.
In that context, running shoes like the Asics Kayano Lite V2, Saucony Triumph 19, and even the adidas Solarglide 5 compares – at least on a conceptual level.
Out of the three, we find the Asics Kayano Lite 2 to be the closest match. Not only is its weight, price, and heel offset identical to the Glycerin 20, but its cushioned yet stable ride delivers the same performance outcome. We reviewed the Kayano Lite V1, and it’s nearly identical to the V2. Go on, read our review.
The Saucony Triumph 19 isn’t bad either, and if you want god-tier levels of stability, the Boost-equipped adidas Solarglide 5 could be your shoe.
By the way, Brooks also sells the Stealthfit variant of the Glycerin 20 with an identical ride but with a stretch knit upper. For reasons mentioned in our upper fit section, we prefer the standard Glycerin 20.