Tuesday, April 12, 2022

Brooks Glycerin 20 Multi Tester Reviews: 4 versions with energetic DNA Loft v3 supercritical foam. 12 Comparisons

Article by Joost de Raeymaeker, Alex Tilsley, Peter Stuart, Ryan Eiler, Jeff Beck, Beto Hughes and Sam Winebaum

Brooks Glycerin ($160)


The Brooks Glycerin has been the brand’s plush neutral daily trainer over the years. In 2021 the 19 introduced a 2nd version with GTS (Go-To-Support) Guide Rails for adaptive stability. 

In 2021 we get 4 versions as the classic neutral and the GTS versions will each now come in two upper choices: regular upper a very soft, pliable engineered mesh and Stealthfit a lighter knit upper that reduces the spec. weight of each underfoot flavor. 

For some weight perspective the lightest shoe is the non GTS Stealthfit upper version (shown above) at light 9.65 oz /274g US9  and the heaviest the GTS with regular upper at a very stout 10.9 oz / 309g  (shown below) with the GTS Guide Rails accounting for about 0.5 oz of the difference.

Joost (Glycerin 20 Stealthfit)

At version 20, the Glycerin is no longer a teenager. However, it is my first Glycerin. I checked reviews of past versions and Brooks’ own information of this new version to see what I might have been missing all these years. The Glycerin is the luxury max cushion shoe in Brooks’ lineup. After launching the mild stability GTS version, together with the standard one last year, this year there are none less than 4 different versions of the Glycerin. There’s the mesh upper GTS and non-GTS and a new Stealthfit GTS and non-GTS version. Stealthfit is a slightly stretchy knit-type upper that hugs your foot and is a single tongue-less piece. The mesh version also has a new engineered air-mesh upper, which is breathable and offers an improved fit. The main difference is that now the Glycerin has the DNA Loft v3 midsole and a slightly different outsole on a widened platform for extra cushioning while offering enough stability and per Brooks’ documentation, smoother and easier transitions. Let’s see what this all means on the run.

Alex  (Glycerin 20 Stealthfit)

I last ran in the Glycerin in 2016 (I think it was the 13, but my memory and training logs are hazy). I picked it up because my favorite shoes at the time – the Kinvaras – were giving me some ankle troubles and I needed something with a little bit more shoe. The Glycerin fit the bill without being offensive in anyway, and I ended up enjoying them so much I ran a half in them (and PRd!). So, I was pretty excited to see a new pair of Glycerins show up, especially when I’d just started having issues with the same ankle. Would the Glycerin 20 be the answer to all my problems? 

Sam: (Glycerin GTS 20 Regular upper)

It’s been a long time since I ran a Glycerin. I found older versions indeed plush all around and quite ponderously soft and dull. Like pillows or even quick sand. 

The Glycerin 20 and in my version the GTS version with the regular upper had me paying attention for one key reason. All versions get Brooks DNA Loft v3 supercritical foam which delivered a fantastically energetic and fun ride in the 2021 “concept car” Aurora-BL (RTR Review) a super light max cushion trainer with a far out, like outer space (the intent) visual design.

Jeff: (Glycerin 20 Regular)

It seems like I’m the oddball here, because I’ve run in a LOT of Glycerin models over the last decade - I believe starting with the Glycerin 8. I missed a few in the early teens, but otherwise I’ve logged some solid miles in most models and the Glycerin 16 was my first review for RTR - so every year a new Glycerin lands it feels like my anniversary reviewing shoes. 

The reason I want to make it clear how much time I’ve spent in the Glycerin is because I’m going to spoil this whole thing right here for those of you who don’t like reading everything - this is without question the best Glycerin Brooks has ever made. It’s not close. It’s that good. There’s going to be plenty of detail below, but if you need to know the story has a happy ending before you start, rest easy. This one is seriously good.

Ryan (Glycerin 20 Regular)

The Glycerin (19) of last year was fine. It was nothing particularly special, with a luxurious and roomy upper, as well as a healthy, bulging chunk of what was presumably the original ‘DNA Loft’ (as opposed to this year’s DNA Loft v3). I never managed to figure out the transition of the 19, and it left me feeling like there was something missing midway through my stride. That version of DNA loft also felt like it didn’t return a whole lot of energy — perfectly acceptable for a long/recovery shoe, but not exactly an inspiration to get me out the door. So it appears that Brooks, rather smartly, decided to shake things up and play with some new midsole formulations and geometries. 

The DNA Loft v3 midsole  here is unmistakably huge — too huge, or just right?

Peter: (Glycerin 20 Stealthfit) 

I ran the Glycerin 17 and was surprised at just how much I enjoyed them. This is the first Glycerin I’ve run since then–and I don’t know whether it’s the Stealthfit or the evolution of the slab of foam underneath, but let’s just say that Jeff and i had very different experiences with the Glycerin 20.


Literally a foam/midsole/outsole to run forever and a day on: energetic, deep, stable, pleasing, smooth rolling, lighter than weight: Sam/Beto/Jeff/Ryan

Very smooth nitrogen-infused midsole Joost/Beto/Jeff/Ryan/Sam

Soft, stable ride - Alex/Beto/Sam/Jeff/Ryan

Pleasant fit (Stealthfit upper) Joost/Beto/Peter

Stealthfit weight just under 10 oz / 283g for my  M9.5 Joost

Could wear these shoes all day - Alex/Jeff/Peter 

Stealthfit is an easy on and off shoe and still very secure lockdown. - Beto

Stealthfit fits like a glove and the lockdown is just perfect and secure. - Beto

DNA Loft V3 midsole, flexibility, and stability make easy runs fun-Sam

GTS support Guide Rails not noticed and likely useful for neutral runners given the soft foam and fairly loose comfort fit regular upper version I have: Sam

DNA Loft v3 bounce is more subtle than the Aurora B;sL- Jeff/Sam


Weight is way up there 10.9 oz US9 in my GTS with regular upper especially given DNA Loft v3 supercritical foam and how light the similar Aurora-BL was. My regular upper over built and over plush? Maybe, but this is a Glycerin after all! Sam

Stealthfit upper a bit warm for warm climates (Africa and Mexico)  Joost/Beto

In spite of the nice transitions, a bit of a dull ride Joost/Peter

Took me a couple runs to get the midsole to feel smooth (though now that it is, it’s great) – Alex/Sam

Midsole platform is very wide Jeff/Sam

Plush upper provides slightly too loose of a fit Ryan/Sam

Over-engineered midsole for lighter runners Ryan

Makes me want to take up a different sport Peter


Sample Weights: 

  men’s GTS regular upper 10.9 oz  / 309g (US9), non-GTS Stealthfit (US9.5) 282g /   9.95 oz. (US12), non-GTS Stealthfit  320g / 11.2 oz; non-GTS regular upper (US10.5) 11.1 oz / 316g

Stack Height: 34 mm heel / 24 mm forefoot, 10mm drop 

Available now including at our partners at the end of the article. $160  

First Impressions and Fit

Joost: Let’s get this out of the way: The gray Stealthfit version of the Glycerin 20 is, well, gray. It looks a little dull compared to the mesh upper versions. The dark blue accents and laces don’t help much. The Glycerin fits true to size for me, with ample space in the forefoot and a secure midfoot. The DNA Loft v3 foam feels soft, but with enough firmness to not get the sensation that your feet sink into it. As a max-cushioned shoe, there’s quite a lot of it, too. So, we have a luxury max cushion shoe with a great fit and a great foam. Everything seems set for a great review. Let’s dive in and see where the Glycerin shines and where it doesn’t.


I’ll be honest, I don’t love the look of this shoe. The women’s blue and lavender colorway on the non-Stealthfit version is fine, just not my personal preference. But the midsole has sort of a beveled edge and a plastic-y look that makes it look more orthopedic than my personal preference. I get that this is a big shoe, but I wish it didn’t look so big. 

Putting them on I started to warm up a bit to the Glycerin 20. It immediately felt soft and bouncy, the upper fit like a glove, and I was ready to go for days (minus the afore-mentioned bum ankle). 


The Glycerin 20 Stealtfit fitted me perfectly. The sample is US12 and fitted me like a perfect US12.5 thanks to the ample space up front. The midfoot feels very secure and the heel counter has no issues and no slippage. The DNA Loft V3 midsole has just the perfect amount of soft but not a sink in feel. It is very comfortable when walking and very energetic when running. 

Jeff: My Regular/Regular (standard upper, non-GTS version) showed up in the local Denver Broncos blue and orange colorway, and looked a little understated right out of the box. I’ve put a lot of miles on last year’s Glycerin 19, and spent a fair amount of time in them casually after retiring them from running service, so I’m very familiar with how the modern Glycerin looks and feels - and the Aurora BL (Brooks’ first shoe with DNA Loft v3) was my road shoe of the year last year, so I thought I knew what to expect. My immediate takeaway was that the Glycerin 20 is a very solid marriage of a Glycerin and the Aurora. It’s not either of those shoes, but takes elements of both very cleanly. It reminds me a bit of the Impossible Whopper from Burger King - yeah, it’s Impossible Meat instead of beef, but there’s no mistaking that it’s a Whopper. This shoe has something else underneath the foot, but there’s no mistaking that it is absolutely a Glycerin.

Fit is spot on true-to-size for length, although the Regular/Regular is a very high volume shoe. I’ll get into it more down below, but the overall platform is much wider than the G19. At every point it is a few millimeters wider, but it’s one of those things where the whole is much greater than the sum of its parts - a few millimeters here and there really adds up.


The smooth, bright white midsole looks massive out of the box. My M9.5 fit true to size, with a spacious fit thanks to the plushness of the upper. It feels slightly heavy, but not so heavy as to be intimidating. The firmness of the DNA Loft v3 midsole communicates that it intends to provide a supportive platform, albeit with more bounce than a traditional daily trainer. At rest, there’s a ton of ground contact given the midsole’s shape , which as you’ll read later, provides for an exceptionally seamless transition.

Peter: Fit is true-to-size and the step-in comfort is great. The Glycerin 20 Stealthfit feels good on the foot. I’ll say that the knit upper seems pretty outdated. I’ve been happy to see knit shoes receding from the market–and this looks very 2019 to me. There’s a big slab of foam here and on first touch it seems less flexible than previous Glycerin models. 

Sam: My regular upper GTS pair is a half size up from my normal. The step in feel, always a Brooks strength is sublime from underfoot to upper feel. I immediately noticed no gusset tongue, in my view a big no no in a soft thin Jacquard mesh upper as we have here and something that impacted the fit (loose at midfoot and collars) of the recently reviewed (an now similar also in ride) 880v12 from New Balance.  I sure was happy that I had the GTS version to stabilize things and for sure regretted even with GTS not receiving true to size as the loose fit impacted the performance. No one should size up for width here given the loose upper. Get the wide version if you need to and if you have a very narrow foot potentially consider sizing down or maybe if typically in a men’s version try the women’s version. 


Joost (Stealthfit version)

The Stealthfit upper in my version of the Glycerin 20 reminded me of some of Nike’s Flyknit uppers. The one I had that was most visually similar was the Epic React Flyknit. The likeness isn’t only visual. They feel very similar, too, in spite of some obvious differences. The Glycerin ticks the typical knit upper boxes like a denser knit in areas that need to secure the foot, or give support and a more open knit over the forefoot, in order to provide some breathability. The upper is a single piece, meaning there is no real tongue. The lacing/tongue area and the collar are more stretchable. This helps with getting them on your feet and also leaves room for some adjustment via lacing to secure your foot. People with a voluminous foot will hardly need the laces, while people with narrow and low volume feet will need them to secure their foot. 

There is some additional material on the inside of the toe area to create some volume and there is internal padding and stiffening in the heel and ankle area to provide support and secure the heel in place. 

The Brooks logo overlays on either side of the Glycerin provide a tiny extra bit of structure to the midfoot. The eyestay is made of a cord that’s stitched into the upper. 

The laces pass underneath the cord in the areas where there’s no stitching. The stitching itself is on the edge of the more densely knit part of the upper, providing the support to allow for the laces to secure your foot. Overall, this is a fine and very comfortable upper, which secures the foot nicely in place. My only criticism is that it’s quite hot and not as breathable as a mesh upper. You might want to pick the version of the Glycerin with the mesh upper if you’re living in a warm climate.

Beto (Stealthfit Upper)

The Stealthfit Upper as Joost said reminded me of the Infinity React but for me it was more like the Adidas Ultraboost Uncaged version. The Glycerin 20 Stealthfit upper only has a bit of padding in the heel area to secure the heel in place, the heel collar doesn’t bother when wearing  low socks so good on that and the midfoot has an internal cage similar to the Ultraboost Uncaged but with a more relaxed fit. 

The lacing system really works well and is very secure with those different loops in the tongue. If you are using a Stryd just release the bottom loop and use the middle one. The upper is a booty knitted upper and the toe box has volume and feels very comfortable and breathable too. It’s a simple and relaxed design which I like and is lighter too.

Peter: As I mentioned above, the Stealthfit upper looks and feels like shoes from three years ago. I’m not a huge fan of knit uppers, and I think that even though this upper feels good on the foot and holds decently, it still contributes to the lack of harmony of the shoe. I think that a mesh upper might do a better job of locking the foot down to the midsole. For me the weight savings of having the knit upper isn’t worth the trade-offs. It’s comfortable, but ultimately doesn’t help the overall feel of the shoe for me. 


I have the regular upper, and while not as exciting as the Stealthfit, it’s pretty great. The mesh is soft, has just enough stretch to still hold my foot in place, and it breathes. I found it had plenty of volume, the laces were secure, and the heel collar is not too bulky. All in all, it’s the perfect upper for this shoe. Not flashy, but absolutely nothing to complain about. 


I have the standard upper and it is nearly identical to the Glycerin 19’s upper that we all raved about a year ago. The mesh is super breathable and soft. The toebox isn’t Altra wide, but it’s plenty wide, and foot hold is executed well. One of the few changes is to the tongue, which now has a pull tab on it. Personally I prefer pull tabs to be on the heel than the tongue, but tongue is better than nothing. I had to confirm if the tongue was gusseted or not (it is not) because in more than 50 miles of running (and a number of casual days at the office) the tongue had never strayed off of center - that’s how dialed in the fit is.

Ryan (Standard upper)

Every part of the upper strives to provide comfort mile after mile, with a layered mesh surrounding most of the foot. It’s a very similar construction to that of its predecessor, the Glycerin 19. While I appreciate the drama-free and very comfortable plush feeling it delivers, at times it felt a bit loose, especially in the toe box. 

The mesh is nicely sculpted with minimal overlays, allowing it to conform to nearly any foot shape. At the back, the heel is generously padded, and the heel counter is very solid. As a high-mileage trainer, it largely accomplishes its goal of delivering a reliable, worry-free foot hold at easier paces.

Sam: This soft plush regular upper is not supportive enough around lace up and just behind. I have a medium narrow foot. It feels great at try on and on foot walking around but on the run it cries for some more substantial overlays, a gusset tongue and a firmer ankle collars to really lock the midfoot and recall the GTS is a light stability shoe. While underfoot is stable up top most support/stability shoes have at least some additional medial upper support via overlays, straps, or denser mesh. Nothing here.



The main differentiator between the Glycerin 20 and the 19 is the new DNA Loft v3 midsole. DNA Loft v3 is a nitrogen-infused supercritical foam that was first used in the Aurora BL (RTR Review), which is a Brooks’ Blue Line (hence the BL) concept shoe. The Blue Line department is where the company’s cutting edge technology is developed. Then technology such as here DNA Loft v3  is adopted in the traditional lines like the Ghost, Caldera 6 trail (RTR Review) and the Glycerin 20. 

According to Brooks, the foam is their softest lightweight cushioning,  it’s responsive, durable and offers plush comfort. 

Unlike the decoupled midsole of the futuristic looking Aurora BL, the Glycerin has a single block of foam that has a (for lack of a better way to describe it) soft firmness to the touch. This translates into a soft and relatively responsive feeling on the run. It definitely feels very comfortable and should be the kind of foam that can keep you going for hours without every feeling like the softness from the start of your run is gone. There’s also quite a lot of it. I unscientifically measured 34 mm in the heel without the sock liner (which is a standard Ortholite affair) in my men’s 9.5US. The base is approximately the same as the Glycerin 19 in terms of width, making for a very stable shoe.


As Joost lays out, the Glycerin 20 has a new, nitrogen-infused supercritical foam that Brooks says is its softest foam yet. At first, this was not my impression. I found the midsole hard under the forefoot, and could only really make the shoe feel good if I intentionally ran back on my heels. After a few runs, though, it felt like the midsole opened up. Since those initial runs, I’ve found the midsole to be soft but not dull. Plenty of cushion to go for days, but it doesn’t feel like the cushion is slowing you down. 


The midsole of the Glycerin 20 made of DNA Loft v3 which is a soft and responsive foam. The first thing I noticed when I started running this shoe was I felt  it would be fun and fun it is. The DNA Loft V3 feels soft with just the right amount of density not to feel a sink and gives an energetic bounce so is a responsive midsole and works really good and balanced in the Stealthfit Upper giving the shoe a lightweight feeling. The midsole doesn’t crease/compress much which helps deliver a stable ride at easy pace and moderate paces and for longer runs. I gotta say I really did enjoyed that a lot such that on long runs I didn’t even have to look at the watch much.


This was the shoe I’ve been looking forward to since my first run in the Aurora BL. Immediately my mind went “Yeah, this is great, but what would a Glycerin run like with *this* midsole material”, and ever since it’s been the waiting game. Not a huge surprise, the result is pretty great, but it is surprisingly different from the Aurora BL. The Aurora’s design is much lighter, and I measure it as 3mm lower stack in the heel than the G20, but it is also much, much bouncier. Like Nike ZoomX Invincible levels of bounce, but that isn’t present here in the Glycerin. Maybe it’s the single gigantic slab vs two separate pieces, maybe it’s the thick rubber coating, maybe it’s the different geometry, whatever the reason, the Glycerin has a nice suggestion of bounce while the Aurora is approaching superball levels of bounce. 

As much fun as super bouncy shoes can be, I’ve personally found when I log miles in them most days of the week it’s only a short amount of time until I start getting lower leg issues and land myself on the injured list - but that’s not a concern with the Glycerin 20. It seems like they’ve pulled back on the bounce just enough that the result is a shoe that’s bouncier than most, but not enough to cause problems.


The DNA Loft v3 strikes a nice balance of responsiveness and stability. It is very obviously a different compound than past versions of DNA Loft. While this midsole is fairly firm, preventing the chunky stack from acting out, it still manages to provide a bit of pop that you won’t find in more traditional, EVA-esque compounds. There is an absolutely massive helping of the stuff here, making this an ideal high-mileage workhorse that excels at beating back even some of the roughest, toughest asphalt. However, it may be a little excessive for lighter runners who don’t need such a copious amount of protection. 

For my fairly high cadence, midfoot strike, and ~145lb mass, it felt like I wasn’t getting the full benefit of all of that DNA Loft. This may very well be an excellent high-mileage trainer for runners that have more upper body muscle than I do, though! The extra material works well to significantly dampen road impact, and I won’t be surprised if this midsole ends up lasting for well over 300 miles.

Peter: As the grouch here I’ll say that the huge slab of foam feels like…a huge slab of foam. I don’t find it to be flexible, bouncy or smooth. I’ve had a few runs in them and am still waiting for them to “open up”. If they do, I’ll report back, but my experience is that the foam feels dense and kind of clompy. Not a fun shoe for me to run in so far . Perhaps if there was some more flexibility I’d enjoy it more. 

Sam: The Loft v3 midsole foam retains the soft plush Glycerin ride and gives it smooth energy. It took a few runs to break in the midsole and outsole flex so bear with it but once there you will have a smooth fun midsole that is clearly on the soft size. The platform is broad and a bit lumbering but for the Glycerin in my GTS version the actual return of the foam, its soft yet very noticeable rebound and its level of protection are outstanding for those easy days. Of course the outsole plays a key role in holding it all together.

The GTS (Go-To-Support) Guide Rails are a foam rail of the same foam as the midsole on the lateral side (shown above) and a medial rail of a co molded (no glue layer) slightly firmer foam (shown below).

More focused on stabilizing the knee than controlling pronation per say. If you tried recent GTS shoes such as Launch GTS 9  you will notice these rails are very subtle and I hardly noticed them at all on the run. Given the sloppy upper fit just above the rails, I am happy they are there. Without them I doubt I could adequately  run my half size up pair and likely neither a true to size. Despite my usual dislike of most knit uppers I am pretty sure the Stealthfit would solve these issues.



There’s a slightly different outsole structure, while still very similar to the previous version of the Glycerin. According to Brooks, this new design makes for a smoother and more stable transition. I find it provides just enough longitudinal stiffness to add support to the relatively soft midsole. It’s decoupled from the heel all the way to the toes. Traction is ok and durability should be in line with other Brooks shoes.


The outsole is stiff with some strategic breaks to give the shoe a little bit of flex. This seems to make for a stable ride that still transitions well and doesn’t feel clunky if you pick up the pace a little bit. Traction has held up fine, and it seems like it should be durable, though it’s too soon to tell.


There is a lot of outsole rubber on the Glycerin 20 and the traction is good on any road or compact trail as well as on wet roads. The main thing I notice is how durable this outsole is. I ran 85 miles in this shoe and the outsole is holding pretty well even at my normal wear areas. The forefoot outsole is a blown rubber which is firm to the  touch and that actually gives a nice pop in combination which also helps make the shoe more stable at landing from heel to toe. The lateral heel piece is firmer rubber.


The massive rubber outsole is a slight evolution from last year’s shoe, with only a little bit of exposed midsole in the center of the shoe in the heel as well as in the midfoot along the lateral edge. I’ve been putting most of my miles on this shoe to test durability, because the exposed lateral edge is normally where I land, and in Glycerins past that DNA Loft v1 would get torn up pretty quickly. I’m happy to say that the exposed v3 is holding up much better than the exposed v1, and should not be an early failure point. Also, with more than 50 miles on the rubber, there’s very little wear, so I’d expect these to be among the more durable big cushion daily trainers.


A very similar outsole to last year’s, this thick and soft rubber delivers a pleasantly mellow feeling during foot strike. It both protects and deadens a considerable amount of ground feel. 

With the midsole bulging out around the edges of the outer, I’ve noticed a bit of wear on the lateral edges of the DNA Loft already, but there seems to be enough outsole material to prevent this from becoming a real problem. Given the flatness of the underfoot geometry, there’s a relatively high amount of outsole material in contact with the ground at any given time, further enhancing traction and improving the ride.

Peter The rubber hits the road. I wish it was more flexible. 

Sam: Copious soft outsole here. It is well matched to the midsole and stabilizes the soft DNA Loft v3, has effective deep decoupling groove to help get past that flat on the ground midfoot area and iis very quiet on the road, always a sign of well matched materials and effective geometry in a trainer. Plated loud racers are a different animal and purpose and are often noisy

The underfoot profile is quite flat in geometry contributing to stability and when new a bit “flat footed” and dull and lumbering in transition. Fortunately after a few runs the outsole (and midsole) developed good enough flex to improve transitions but overall the Glycerin is not particularly flexible with its flex point way back towards midfoot. 



So what does this add up to on the run? The Glycerin has the great advantages of a modern supercritical foam, being soft while not bottoming out, not too heavy and also quite responsive. It transitions easily enough, but it definitely doesn’t feel like a shoe you could go fast in, and that’s also not its intended use. The decoupled outsole helps in guiding your foot while you’re in contact with the ground. Its upper (Stealthfit in my case) secures your foot well over the big slab of DNA Loft v3 and makes for a great easy run and recovery shoe. The luxurious feel and the soft ride also make it a great option for those long slow distance runs.


As I’ve mentioned, the ride really changed for me after a couple of runs. The first couple were dull, hard, and honestly unpleasant. But by run three everything changed. The Glycerin 20 is soft but has enough flex and bounce to keep you rolling forward all day long. It does feel a little heavy on the run, but this is a shoe for the days when you don’t mind wearing something heavy. This is not a speedwork or tempo shoe, but for those days in between when your legs are tired and you just want a shoe that feels good as you shuffle through some recovery miles, you could do far worse than the Glycerin. 


Exactly what Alex said. The ride is not fast, that's for sure given the weight and broad platform. The Loft v3 foam gives me a sigh of relief that the ride would not be a chore given its lively soft energy. The feeling is one could run all day through the night and on to the next day, easy does it, smooth and plush but never mushy soft and relatively easy to transition given its flex at moderate and slow paces. 

Given the shoe’s weight, it does not exactly have a snappy responsive ride, and with my Regular upper issues the ride is strictly moderate and easy days and trippy LSD (long slow distance) for me and a fine option for that. With the lighter and more secure Stealthfit upper versions, I think I likely would have the Glycerin leaning somewhat more towards daily training and all around use.


Alex and Joost are absolutely right, this is a shoe that’s got some nice softness but also some bounce to it. As much as I enjoyed the ultra bouncy Aurora BL last year, the more conservative bounced Glycerin 20 is much easier to live with. A year ago I enjoyed the Glycerin 19, but it was very much the best of the big cushion but still “Plain Jane” trainers that you put a bunch of miles on, but maybe don’t have a huge smile the whole way. I still don’t think the Glycerin 20 is a huge smile shoe, but I think it’s a little smile shoe, maybe a big smirk, but it’s a big smirk you can put virtually all of your easy miles on and not have to worry about the extra wear and tear all the big bounces are putting on your lower legs. 


As Joost, Alex and Jeff said and they are right.

My first run was for an easy run and the shoe felt a bit firm but at the end of the run the shoe felt more energetic and the next run the shoe felt amazing,  soft and responsive and very well balanced. 

On some easy runs I was 20 seconds faster than my normal easy pace so the midsole really helps you cruise along on those runs and as you lower the pace the shoe feels soft and bouncy. 

On a progression run I started slow and felt the soft and bouncy ride but as the pace started to pick up the shoe feels more energetic which make a fun ride and the only other shoe I enjoyed that feeling was the Triumph 19 well balanced and soft and bouncy with that energy return to cruise the miles. TheGlycerin 20 reminded me of that feeling with a more energetic ride.


A flat and decidedly non-rocker shape underfoot, no drastic midsole cutouts, and a firm slab of foam make for a highly predictable, sure-footed ride. Even though they run an ounce lighter than their weight on paper, there’s definitely some added inertia to this design. It’s not so apparent at easier paces, but go and try a few strides, and things start to feel blocky very quickly. 

I concur with the other reviewers in that these deliver a pleasant, seamless ride. From heel to toe, the transition is fluid, without any weaknesses or imbalances laterally or medially. For better or worse, the sensation is very disconnected from the ground. While there is a noticeable amount of bounciness from the DNA Loft, it’s firm enough that it doesn’t necessarily feel deep. Toe-off isn’t anything special, but snappiness isn’t what this shoe is about. A very pleasant ride made for turning on the cruise control and knocking out an above-average number of miles.

Peter: I’m going to have to try another couple of runs in these apparently. I still haven’t found any fluidity in the ride or enjoyment on runs. Perhaps after a few more runs they will “open up” as others have said. So far, no dice. 

Conclusions and Recommendations


My first Glycerin and I like it a lot. It feels very comfortable, has a responsive softness about it that’s complemented by the great fitting Stealthfit upper. As an easy run or recovery shoe, it ticks all the boxes for me. Enough support, soft and forgiving for tired feet, not too heavy and an easy going ride that can take you as long as you want. It’s basically everything the Nike ZoomX Invincible Run Flyknit was hyped up to be, but never was.It’s  not the least expensive of daily miles shoes , but durability should be great, and of course you pay a little extra for that luxurious feel.

Joost’s score 8.98/10 (Ride 8.9 - 50%, Fit 9.5 - 30%, Value 8.5 - 15%, Style 8 - 5%)


I will admit, I had such fond memories of my old Glycerins that I felt a little let down by the 20. I remember loving the Glycerins because they were soft but didn’t feel slow, and they flexed in a way that made them feel responsive. This could be a rose-colored glasses situation, but I don’t love the 20 quite as much as I remember loving the 13 (or 14?). Don’t get me wrong – it’s a good shoe, and I’m going to keep it in my rotation for those long run miles, but the Glycerin 20 definitely lets you know it’s meant for the easy days. Runners looking for a neutral, plush, no-nonsense ride should definitely give the Glycerin 20 a look for those long or easy miles

Score: 8.8/10

Ride: 8.5 (soft and stable, but lacking the fun factor for me)

Fit: 10

Value: 8 (you definitely pay for the extra cush!)

Style: 7 


This new midsole works and performs very well. New midsoles are starting to come to the heavy duty and high cushioned trainers such as the Glycerin 20. In this version the DNA Loft v3 plays an very important role and Glycerin is not only a high cushioned shoe or slow mileage trainer but it is now softer, bouncy and more responsive so it is a very nice update if you are a fan of the Glycerin line or want a highly cushioned shoe that can also pick up the pace and want to feel that extra energy return at each step while still staying stable.The Stealthfit Upper is a great addition to the line up as it gives a nice look and style, it reduces weight while also not compromising an important element of a high cushioned shoe which is comfort and lockdown.

Ride: 9.8 (50%) Fit: 9.5(30%) Value: 9.0 (15%) Style: 10 (5%)


The Glycerin 20 feels to me like a shoe that’s gone through a few internal iterations before we got to see the final result. Brooks had tinkered with their new midsole for a year before unleashing it in their big daily trainer, and as a result it isn’t quite as out of control as the first shoe outfitted with DNA Loft v3. But they didn’t change their overall formula, sticking with an outstanding, if a little boring, upper, and slapping a very durable but flexible outsole on the bottom to give it plenty of durability to help blunt the sting of the price tag. The overall fit is very big, and could require some runners to tinker a bit with lacing to get the fit really dialed in, but that means it will accommodate virtually all feet and it is also available in wide. 

For me, not having to limit my miles in them (to avoid achilles tendonitis flare ups that super bouncy shoes cause me 100% of the time), but still giving more bounce than a standard midsole foam puts it at the front of the pack for the best shoe of the year, even just a few months in. Brooks has set the bar high, can anyone else clear it?

Jeff’s Score 9.5/10

Ride: 9.5 (50%) Fit: 9.5 (30%) Value: 9.5 (15%) Style: 9.5 (5%)

Peter: Some shoes just seem to work better for some people than others. Even though some of the other reviewers have found the Glycerin 20 to “open up” after some miles, I’ve still found them to be sort of dull and clunky. I’m curious as to whether the Stealthfit adds to the general blah of the Glycerin for me, but it may be that it’s just not a shoe that works for me. I find that I feel like I’m working against the Glycerin when I’m running rather than working with it. 

Peter’s Score 6/10

Not really a fit for me. I’ll report back after a couple of more runs if anything changes. They feel clunky and there are just too many shoes out there that I enjoy running in more. 


I think of this shoe as the reliable workhorse of the fleet. While it doesn’t excite, set PR’s, or turn heads, it accomplishes its intended job of providing gobs of stable protection for large amounts of mileage. The upper is supremely plush and voluminous, the midsole looks as if it may never wear out, and the slab of rubber underfoot provides a sure-footed feeling. It’s a shoe meant for racking up casual miles and preventing injury, especially for runners who always desire more protection. I think Brooks has found a keeper in their Loft v3 compound for long stints of moderate road running.

Ryan’s Score: 8.9/10

Detractions for a loose fit from an overly plush upper, above average weight, and an over-engineered midsole for lighter runners.

Sam: The star feature here is clearly the DNA Loft v3 midsole foam. Soft, energetic and Glycerin appropriate plush it delivers a superb, fun ride feel. Then things start to go south for me. The regular upper is clearly super comfy, soft and plush but isn’t as supportive as it could be and particularly in my GTS support Regular upper. What no gusset in such an upper in general and especially in a support oriented shoe?  No reak medial reinforcements higher up to go with the effective and even for me as a neutral runner kind of essential here Guide Rails to help support the foot at the critical lace up and rear collar area?

There is hope! The Stealthfit upper versions likely would be more supportive and in a twist the similar stack height trail Caldera 6 (RTR Review) also with DNA Loft v3, high stable side walls all around and a very supportive gusseted upper.  While a bit heavier yet, and with a trail outsole, if you need a long slow road and recovery days trainer that of course can trail also please consider it.

Sam’s Score: 8.79 /10

Ride: 9.3 (50%) Fit: 7.8 (30%) Value: 9 (15%) Style: 9 (5%)

12 Comparisons

Index to all RTR reviews: HERE

Brooks Glycerin 19 (RTR Review)

Jeff (M10.5 in both)

The 20 put on a little weight, but gained a lot of stack height and width, and transformed the shoe from being a really good soft daily trainer to a class all by itself. We had to have the 19 to get to 20, but the 20 feels like it could be five generations later than the 19, it’s that big of a step forward.

Ryan (M9.5)

The most notable differences between this generation and the 19 are the increased stack height of the 20, with its spunkier DNA Loft compound, and the smoother and much improved transition of the 20. I agree with Jeff that this shoe has come a very long way in just one generation. While the upper is extremely similar, the new midsole foam has a lot more energy and doesn’t feel as dead as the 19 did. Whereas the 19 had a slightly more curved shape underfoot, the 20 is much flatter, resulting in a noticeably more continuous transition from heel to toe. Version 19 felt a bit confused and clunky at times, but the DNA Loft v3 upgrade has largely fixed those problems, resulting in a highly protective yet reactive shoe that is much more enjoyable to wear on recovery runs. The 20 wins this contest hands-down.

20 vs 19

Nike Zoomx Invincible Run Flyknit (RTR Review)

Joost (M9.5 in both)

The Glycerin 20 is everything the Invincible was supposed to be, but isn’t. Better ride, better upper, more stable, better overall feeling on foot . No contest. The Glycerin wins with a KO.

Jeff (M10.5 in both)

I most agree with Joost. I think the Invincible’s super bouncy nature is more fun, but more fun doesn't make it a better shoe. The Glycerin 20 is much easier to live with and run in on a daily basis.

Skechers Razor Excess (RTR Review)

Joost (M9.5 in both)

This is more about supercritical foams than the place of the shoe in the lineup. I’m a huge fan of Skechers Hyberburst, and there’s a copious amount of it on the Razor Excess. Where Skechers has failed me time after time is in the upper department of their performance oriented shoes. I would grab the Glycerin 20 for my daily workouts and longer runs and the Razor Excess for faster and shorter work.

Saucony Ride 14 (RTR Review)

Joost (M9.5 in both)

I know the 15 has just come out, but I’m still on the 14. Comparable in target audience and runs. The Glycerin is the better executed shoe for me because of the DNA Loft v3 midsole. The Ride 14 feels a bit dull in comparison. My vote goes to the Glycerin.

Jeff (M10.5 in both)

100% agree, the Ride is a really good, if pedestrian, daily trainer. The Glycerin is better, and not pedestrian at all.

Beto: (M12.5 in both)

I agree, the Ride 14 is a very good daily trainer for almost any training session but it lacks that responsiveness at some efforts. the Glycerin 20 has that new DNA Loft v3 which makes it a better option to do almost all types of training. Maybe not faster tempos but still can do them.

Saucony Ride 15 (RTR Review)

Sam: More than 2 oz lighter than my regular upper GTS, getting close in cushion feel and depth, the new Ride has a far more supportive upper if one not as plush as the G20’s Regular with at least as much real support/stability if you need in a neutral shoe.  It is a modern do it all daily trainer whereas the Glycerin is a plush cruiser for slower miles. The DNA Loft v3 is a superior riding and more fun foam than the much improved PWRRUN but the other benefits of the Ride include weight, more dynamic flow, superior different type of run versatility and its upper easily tip the scales in its favor. I was true to size and snug and supported in the Ride 15 and correctly so for its purposes.

Saucony Guide 15 (RTR Review)

Joost (M9.5 in both)

I got this year’s Guide instead of the Ride for review, and while I’ve only had a couple of shorter runs in it, I can confirm that the light control elements of the Guide don’t really sit well with my stride. If you need a little extra medial support or control, the Guide might be the better choice for you.

Sam: Very similar in all respects and light as the Ride 15 the Guide 15 adds a unique curved and more skeletal medial support piece to the midfoot but otherwise is identical to the Ride 15. It is significantly lighter than the Glycerin GTS in my regular upper version. Want some stability and want to move along Guide. Want some stability to cruise mellow and plush Glycerin GTS.

Adidas Adizero Boston 10 (adidas adizero Boston 10 Multi Tester Review - Road Trail Run)

Joost (M9.5 in both)

The Boston underwent a complete makeover and now comes with plastic rods and much more stack height. The only similarity between the 2 shoes is their stack height. Let’s say the Boston didn’t make it into my rotation and the Glycerin most likely will be my recovery shoe of choice for the coming future.

Beto: (M12.5 in both)

The Boston 10 new makeover changed the shoe but for me making it an Uptempo/Daily trainer. As Joost says the stack is the same but they are two different shoes. The thing I can say is that you can use the Glycerin 20 for those easy to moderate runs and some light tempos and the Boston 10 for those harder efforts where the Boston really shines. 

Brooks Aurora-BL (RTR Review)

Jeff (M10.5 in both) 

Its looks are polarizing, its upper unconventional, and its bounce undeniable, the Aurora-BL was one of the most unique shoes to come out in some time, and I was and am a big fan of it. Unfortunately, its big bouncy ride has caused me a lot of pain and time on the IR, leading me to realize that bouncy shoes may not be the future (at least for me). The Glycerin is the more usable shoe, that gives a little bit of bounce, and none of the achilles pain. Lots of car companies put cool features in their halo car, and then years later those features make their way into the daily drivers. That’s what Brooks did with DNA Loft v3, and it only took a year or so to trickle down.

Sam: The Glycerin with DNA Loft v3 is a “safer” bet. For sure not boring or lumbering with a wonderful midsole  but not exactly snappy or fast  it is not nearly as exciting as the much lighter Aurora BL. I wish Brooks would hurry along something in between these two as a daily trainer. 

ASICS Nimbus 24 (RTR Review)

Jeff (M10.5 in both)

The Nimbus 24 was a big step up for ASICS, using a FF Blast+ midsole and improving and streamlining the upper a great deal. But the effect is evolutionary to the Glycerin 20’s revolutionary glow up, with the ASICS ride paling in comparison to DNA Loft v3.

Sam: Agreed on the foam rides here but in the heavy duty daily trainer category the N24’s notably more secure yet still plush enough upper has me leaning its way despite its less exciting ride. 

New Balance 1080v12 (RTR Review)

Jeff (M10.5 in both)

Another shoe that got much better this year, the 1080 took me by surprise. While it stuck with the same Fresh Foam X they’ve been using for a few years, the shape and volume of the midsole changed, and with it, the entire ride improved by leaps and bounds. At the same time the upper went from “problematic” to “incredible” and the result is a very well cushioned daily trainer that you’re likely to want to log most of your easy miles in. 

Stop me if you’re heard this before, because it lines up very cleanly to the Glycerin 20- part of the reason I made the video below profiling and comparing the two shoes. I’ve put many more miles on both shoes since that video, but my conclusion remains the same. Don’t overthink it. Both are incredible, if you want a little softer ride ? 1080. If you want just a hint of bounce? Glycerin. If your wallet can take the hit and you want the best 1-2 punch of big cushion trainers ever put together? Buy both, alternate them every other day, and thank me later.

Watch Jeff Beck's 1080 v12 to Glycerin 20 Comparative Review

Beto: (M12.5 in 1080v12) 

As Jeff said the shoe uses the same Fresh Foam X its shape changed with the forefoot a bit wider and now I feel less road at each step. The ride in the 1080 improved and feels more stable and works together better with its he rocker from heel to toe. The upper holds my foot in place and is very comfortable too. 

The ride worked for me better at easy to moderate paces but in comparison to the Glycerin 20 which feels more responsive at moderate paces, I feel like the 1080 lacks a bit on responsiveness but the comfort and how the shoe performs when you need that extra protection from the road balanced that lack of energy return. The Glycerin 20 was more fun to run with its energetic and soft midsole, amazing for a do it all high cushioned trainer with the Stealthfit upper giving it a nice style option to the normal Glycerin.

Saucony Triumph 19 (RTR Review)

Beto: (M12.5 in both)

The Triumph 19 was one of my favorite high cushioned shoes for longer runs and I mean I ran a 36k long run and ended up running a Marathon is this shoe.  Iit has a very comfortable upper with a perfect lockdown on my foot, a very soft and bouncy ride that feels energetic thanks to the flexible midsole which also worked for some faster efforts too. PWRRUN+ is a nice midsole that also last a lot of miles and the outsole has great traction dry or wet with lots of rubber for durability. 

The Glycerin 20 reminded me of the Triumph 19 a very similar ride that has a soft but not a sink in feel and a nice bounce. The Glycerin is a more energetic and has a more stable ride so is a good competitor in the same category. For me it is hard to choose between these two but the Glycerin 20 caught me by surprise with this new version of the DNA Loft v3 and is definitely a shoe worth the money, and is durable and fun as is the Triumph 19. 

New Balance 880 V12 (RTR Review)

Peter: The 880 is almost a full ounce heavier than the Glycerin Stealthfit, but feels lighter, smoother, more forgiving and more enjoyable every step. 

Sam: A more flexible agile ride and especially toe off combines with a less energetic foamthan the Glycerin’s. Both have light plush “ regular mesh” uppers with inadequate support. I pick the Glycerin for its more energetic DNA Loft v3 foam ride and hope both get more serious regular esh uppers if not a knit as in the Stealthfit. 

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Anonymous said...

Great review, Sam and ever growing team!

Did anyone who tested the GTS version also have experience with the Kayano 28s? Curious how they compare. Thanks!

Anonymous said...

Wow great review. Very tempted. How does the Glycerin compare to Skechers maxroad 5 and Asics Novablast 2. Thanks.

Anonymous said...

I've not enjoyed the glycerin 19 as much as the 17 and before. It's making me feel caught between locating a pair of 17 or 18 or leaping in faith into the 20. I'm 46kg so.your comments on lighter athletes are interesting to me. I'd love feedback! Thank you

JBo said...

I think you guys are full of crap. Your review of the nike invincible was consistentlt in the mid to high nine's rating. The ratings for the Glycerin 20 were from 6.9 to the high nines. learly the Invincble got higher overall ratings. Yet in your comparison you prefer the glycerin 19. What the heck is going on?

Anonymous said...

Okay, I was super patient with the long review but by the end of it I'm sure I wasted my time going through this. Super vague, inconclusive throughout and especially comparisons with other shoes in the same category. "Effect is evolutionary in Nimbus to revolutionary in Glycerin" right.

Krischen said...

This review was very jumbled and incoherent. The GTS version should have it's own page. Sam was the only one to review the GTS and it appears that he was having an issue with sizing which rendered his impressions of the shoe, questionable. You guys can do a better a job.