Our verdict

The Glycerin 20 from Brooks has totally proved the hype around it! With its luxe comfort and a touch of pop, we found it to be a fun and lively workhorse that works perfectly for recovery days and long miles on the road. Overall, the Brooks Glycerin 20 is a tried-and-true daily trainer that we identified to be a cozy and reliable pick for both beginners and seasoned road runners.

Pros

  • Plush cushion
  • Awesome step-in feel
  • Responsive ride
  • Breathable for hot days
  • Tank-like build
  • Weighs less than looks
  • Awesome value for money
  • Comfortable fit
  • Grippy on wet road and gravel

Cons

  • Laces don't stay tied
  • Heel drop higher than advertised

Audience verdict

89
Great!

Who should buy

We encourage you not to pass up on the Brooks Glycerin 20 if you want a: 

  • comfy and great-value option for both beginners and running veterans  
  • reliable daily trainer for long miles and mellow days on the road

Brooks-Glycerin-20-review

At $160, it may not be the most affordable running shoe. However, if you want a shoe that screams comfort and durability, the Glycerin 20 is one of the best on the market that we have ever tested. 

Brooks-Glycerin-20-value-for-money

Who should NOT buy

If you're a sucker for responsiveness and speed, you can skip the Brooks Glycerin 20. For a smoother, speed-oriented ride, you can go for the  Brooks Hyperion Tempo instead. 

Those who want a set of trusty laces plus the energetic ride, go for the Brooks Revel 5.

Breathability

During warm days, we found that the shoe remains light and breezy. The upper doesn't restrict air and our feet didn't feel toasty at all. We can readily recommend the shoe for summer runs.

See how easily the smoke passes through the fabric in our breathability test below. On a 1-5 scale, where 5 is the most breathable, this Brooks shoe gets a 4.

In the light test, you can also see the areas of the upper which tend to be more breathable.

Test results
Glycerin 20 4
Average 3.8
Compared to 222 running shoes
Number of shoes
1
Breathability
5

Durability

Outsole hardness

Looking at our durometer measurement, we give a nod of approval to the shoe's outsole hardness. At 79.5 HC, it is just as hard as the other road shoe outsoles on average.

Brooks Glycerin 20 outsole hardness

Harder rubbers typically take longer to wear out, so we anticipate at least 400 miles from this Brooks shoe.

Test results
Glycerin 20 79.5 HC
Average 80.4 HC
We use an average of four tests. The photo shows one of those tests.
Compared to 273 running shoes
Number of shoes
54.9 HC
Outsole hardness
92.8 HC

Outsole thickness

The Glycerin 20 also has a good amount of rubber that will help the grip last a while. Using our caliper, we measured the outsole to be 3.5 mm thick, which is the average thickness for road running shoes.

Brooks-Glycerin-20-outsole-thickness

Test results
Glycerin 20 3.5 mm
Average 3.2 mm
Compared to 292 running shoes
Number of shoes
0.0 mm
Outsole thickness
6.6 mm

Weight

The Glycerin 20 looks bulky with all the cushion it gets. However, on foot, it's the total opposite. It feels light and IS lighter than ever. 

Brooks-Glycerin-20-lightweight

Tipping the scale at 10.5 oz (297g) in a men's US size 9, the Glycerin is about half an ounce heavier than the shoes of its kind. For reference, the average weight of daily trainers with a heel stack of 37+ mm is 9.9 oz (281g).

Test results
Glycerin 20 10.48 oz (297g)
Average 9.38 oz (266g)
Compared to 293 running shoes
Number of shoes
5.26 oz (149g)
Weight
12.56 oz (356g)

Cushioning

Heel stack

The Glycerin 20 has a mighty heel stack height of 37.1 mm which is about 4 mm thicker than the average. Actually, only 16% of our lab-tested road shoes went past 37 mm in their stack heights.

That's an immense amount of cushioning and impact protection on the road!

Brooks-Glycerin-20-heel-stack

Test results
Glycerin 20 37.1 mm
Average 33.7 mm
Compared to 292 running shoes
Number of shoes
7.6 mm
Heel stack
42.7 mm

Forefoot stack

The forefoot, on the other hand, is a normcore. Our caliper shows a moderate 24.3 mm of stack height under the toes which is nearly the same as the average.

Brooks-Glycerin-20-forefoot-stack

Test results
Glycerin 20 24.3 mm
Average 25.0 mm
Compared to 292 running shoes
Number of shoes
7.6 mm
Forefoot stack
35.8 mm

Drop

The heel-to-toe drop turned out to be even bigger than claimed by the brand. We measured it at 12.8 mm, while the officially stated drop is 10 mm.

Brooks Glycerin 20 drop

This heel elevation is perfect for beginners and heel-striking runners. However, for those who expect 10 mm precisely, a higher drop could be an unpleasant surprise!

Test results
Glycerin 20 12.8 mm
Average 8.7 mm
Compared to 292 running shoes
Number of shoes
-0.8 mm
Drop
16.1 mm

Insole thickness

To accompany the shoe's above-average midsole, Brooks also used a thicker-than-average insole for the Glycerin 20. Our caliper shows 5.5 mm which is a millimeter thicker than the average.

Brooks-Glycerin-20-insole

Test results
Glycerin 20 5.5 mm
Average 4.5 mm
Compared to 288 running shoes
Number of shoes
1.5 mm
Insole thickness
7.3 mm

Midsole softness

Note: a low durometer measurement equals a soft material, whereas a high measurement means it's firm.

The best way to describe this Glycerin shoe is that it's the beast of comfort. We found the shoe's cushioning to be a major step up from the past versions. 

It's soft with a touch of bounce; it's definitely more fun to run in. Not to mention, it's not the type of plush that bottoms out.

Using our durometer, we found that the foam on the Glycerin 20 is on the softer end of the spectrum. At 20.0 HA, it is 20% softer than the average. 

Brooks-Glycerin-20-cushioning-softness-durometer

Test results
Glycerin 20 20.0 HA
Average 21.4 HA
We use an average of four tests. The photo shows one of those tests.
Compared to 220 running shoes
Number of shoes
8.5 HA
Midsole softness (soft to firm)
41.5 HA

Difference in midsole softness in cold

The shoe's foam also doesn't get much firmer in cold temperatures. After 20 minutes in the freezer, it only firmed up by 23%. Some shoes get up to 60% firmer in the same test. 

Brooks-Glycerin-20-freezer-test-cushioning

Test results
Glycerin 20 23%
Average 25.6%
Compared to 219 running shoes
Number of shoes
0%
Difference in midsole softness in cold
100%

Stability

Lateral stability test

For a neutral shoe with soft cushioning, the Glycerin 20 shows up as a pretty stable running shoe.

We believe that this is due to the shoe's moderately stiff build, semi-rigid heel counter, and wider-than-average platform.

Torsional rigidity

The Brooks Glycerin 20 is not so easy to twist torsionally. In our manual assessment, we rated its torsional stiffness at 3. That is on a 1-5 scale where 5 is the stiffest.

We find it a very welcome touch of support for mildly pronating and tired feet.

Test results
Glycerin 20 3
Average 3.3
Compared to 271 running shoes
Number of shoes
1
Torsional rigidity
5

Heel counter stiffness

The shoe also has an amply padded heel collar which has a medium level of stiffness. In our manual test, we rated it as 3 out of 5 (5 being the stiffest).

We found that it helps to hold the ankle a little better and more securely than the average neutral shoe.

Test results
Glycerin 20 3
Average 2.8
Compared to 255 running shoes
Number of shoes
1
Heel counter stiffness
5

Midsole width in the forefoot

Last but not least, the Glycerin 20 has an extra-wide landing area!

Based on our caliper measurements, it is 4 mm wider than the average in the forefoot (117.4 mm).

Brooks-Glycerin-20-wide-sole

Test results
Glycerin 20 117.4 mm
Average 113.6 mm
Compared to 293 running shoes
Number of shoes
100.5 mm
Midsole width in the forefoot
126.5 mm

Midsole width in the heel

The shoe's heel also flaunts a wider-than-average platform. At 94.2 mm, it is wider than the usual by 4 mm, just like the forefoot.

Brooks Glycerin 20 midsole heel width

But if you do have flat feet and/or overpronation, we recommend going for the shoe's stability version, the Glycerin GTS 20. This version of the shoe comes with the necessary arch support.

Test results
Glycerin 20 94.2 mm
Average 90.5 mm
Compared to 293 running shoes
Number of shoes
74.9 mm
Midsole width in the heel
106.6 mm

Flexibility

Stiffness

Because of its high stack and pretty thick outsole, the Brooks Glycerin 20 loses a bit in the flexibility department.

However, based on our force gauge measurement, it still remains slightly more flexible than the average. It takes 8% less force to bend the Glycerin 20 to a 90-degree angle than it takes a road shoe on average.

Test results
Glycerin 20 28.2N
Average 29.3N
We use an average of four tests. The video shows one of those tests.
Compared to 275 running shoes
Number of shoes
2.2N
Stiffness
94.4N

Grip / Traction

Our test runs showed that the Glycerin 20 sticks well on pavement, gravel, and slick surfaces pretty well!

Brooks Glycerin 20 grip

Size and fit

Toebox width at the widest part

It's just the right fit. We found the Brooks GLycerin 20 to be comfortably snug and our medium-width feet never felt constricted in the shoe. 

Brooks-Glycerin-20-fit

The fact the Glycerin 20 is 2 mm narrower than average didn't make it less comfortable. Our caliper shows 95.9 mm in the widest part of the forefoot.

Brooks-Glycerin-20-toebox-width

Test results
Glycerin 20 95.9 mm
Average 98.3 mm
Compared to 293 running shoes
Number of shoes
89.5 mm
Toebox width at the widest part
109.1 mm

Lacing

The laces on the Brooks Glycerin 20 are a bit of a letdown. They tend to come undone mid-run which was never an issue with the past iterations.

Double-knotting is a must if you don't want to keep re-lacing them. 

Brooks-Glycerin-20-laces

Comfort

Tongue padding

Upon step-in, our feet were welcomed with plush padding from the heel and ankle collar. On top of this, the tongue remained cozy with its amply padded design. Even better, we felt like it stepped up the shoe's lockdown and security.

The tongue is indeed generously padded on the Glycerin 20. Our caliper shows that it is 7.8 mm thick, while the average for running shoes is 5.8 mm.

Brooks-Glycerin-20-tongue-thickness

Test results
Glycerin 20 7.8 mm
Average 5.6 mm
Compared to 290 running shoes
Number of shoes
0.5 mm
Tongue padding
14.2 mm

Brooks Glycerin 20 vs. 19

To cut a long story short, the Glycerin 20 from Brooks is definitely a better version than the 19. The following changes helped to make it happen: 

  • Lighter and softer: The new midsole compound amps up comfort even more. Even better, it sheds off a few grams. 
  • More pep: Apart from elevating comfort, the midsole also makes the Glycerin bouncy, making the ride a lot more enjoyable than before. 
  • Sturdier and stickier: In the outsole, there's plenty of rubber coverage. And for better grip, the flex grooves have also been revamped. 
  • Added comfort: Midsole aside, the upper is also more padded in the heel and the tongue. These do not only make the shoe cozier; they also better the support.

Brooks-Glycerin-20-lab-review

Other versions of the Glycerin 20

Apart from the standard Brooks Glycerin 20, there are three other versions of Glycerin 20, including: 

  • Brooks Glycerin 20 StealthFit - It is a sleeker, snugger version of the standard Glycerin 20. 
  • Brooks Glycerin GTS 20 - It is the Glycerin 20's Go-To-Stability version, perfect for mild to moderate overpronators (whose feet roll inward excessively). 
  • Brooks Glycerin GTS 20 StealthFit - Like the Glycerin 20 StealthFit, it has a more foot-conforming wrap than the regular GTS version.

Brooks-Glycerin-20-lab-measurements