We spent 8.5 hours reading reviews from experts and users. In summary, this is what runners think:

8 reasons to buy

  • Many of the testers appreciate the plushness of the Asics Gel Cumulus 21. 
  • It offers a responsive ride, expressed several runners. 
  • According to quite a few buyers, the running shoe has ample support. 
  • There are some purchasers who appreciate the durability of the shoe. 
  • The neutral running shoe is made of high-quality materials, hailed numerous reviewers. 
  • It has enough room for natural toe splay, commended multiple customers. 
  • Some commenters laud the snug wrap of the shoe around the foot. 
  • Various users admire the versatility of the running shoe.

4 reasons not to buy

  • A number of athletes dislike the bulk of the shoe. 
  • The outsole of the road running shoe is too stiff, remarked some wearers. 
  • Quite a few have observed that the shoe has mild tongue slippage. 
  • According to several experts, the road running shoe lacks breathability.

Bottom line

The Asics Gel Cumulus 21 is a performance running shoe that boasts unparalleled speed and comfort. It provides plush underfoot cushioning when worn during long-distance runs. Loaded with the brand's top-tier technologies, the road running shoe flaunts high-strength qualities and premium energy return. With its generous cushioning, foot protection is also amplified, preventing strain or injury. Overall, the design of the Gel Cumulus 21 does not compromise both style and function.



A top rated Road running shoe
A top rated Asics running shoe
Top 2% most popular running shoes
It has never been more popular than this July
Better rated than the previous version Asics Gel Cumulus 20

Expert Reviews

84 / 100 based on 20 expert reviews

  • 90 / 100 |

    Asics GEL Cumulus 21 review: The dark workhorse

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    I haven’t really been excited for an Asics shoe in the last couple of years. My last Asics shoe was the Nimbus 19: it was expensive, heavy and didn’t wow me.

    It was the first Nimbus to have FlyteFoam in the midsole and it felt very, very firm bordering on hard.



    Here in Asia, Asics is the most popular running shoe brand. Going for long Saturday runs, more than half of the runners I pass wear Asics shoes (mostly Kayanos).

    Whenever I passed them, I would think to myself: shame, it must be torture to run in such a heavy, firm shoe. I didn’t get what all the hype was about.

    I only bought the Cumulus 21 because it was on sale at a ridiculous price. I chose the Cumulus 21 because I have read reviews stating that the Cumulus 21 is actually softer than the Nimbus 21, its older, more expensive big brother.

    I wanted a long-distance trainer that I could use for distances longer than 25 kilometres while I train for a marathon.

    Upper & Fit

    The Cumulus 21 upper is made from Jacquard mesh. It’s thick and plush and feels as luxurious as a Brooks upper.

    It has plenty of forefoot room if you have wide feet and is plush enough to stop your foot sliding around if you have narrow feet. The heel is padded with lots of spongy foam and grips the heel well.



    While the Cumulus upper construction is very old school, Asics keeps it modern with fused overlays and attractive colour schemes. In my opinion, Asics is the best brand at choosing colourway designs.



    I bought the LS (Lite-Show) version of the Cumulus 21. This version has extra reflective lacing overlays as well as reflective paint on the midsole.

    The Lite-Show version came out a couple months after the normal version.



    The Cumulus 21 upper is one of those superlative uppers that you lace up before your run and you don’t have to worry about it for the next 3 hours or however long your run is. No lace adjusting needed, no hot spots, no heel-chaffing. It just works well.

    Midsole & Ride

    The midsole consists of two different types of FlyteFoam: Propel and Lyte.

    One of them is supposed to be bouncier and more responsive while the other is supposed to be firmer and more resilient. Honestly, I can’t tell any difference between the two foams- they are very similar in densities.



    My first run in the Cumulus 21 reminded me of a certain shoe I had a year ago: the Nike Structure 22. The Cumulus 21 feels like a more cushioned, softer Structure 22.

    The ride feels very planted and smooth with a pleasant sink-in feel and none of the rigidity of the Structure.

    While the Cumulus 21 is not a super soft shoe like the New Balance Propel or the Pegasus Turbo 2, it is a very padded shoe and excellent at absorbing shock. If you remove the insole, you can feel the soft, spongy layer that provides sink-in comfort.



    The shoe is advertised as having rearfoot and forefoot gel but that’s just a marketing gimmick.

    There is only a small amount of gel in the heel and a coin-sized gel unit in the forefoot which doesn’t do much as far as cushioning is concerned. The type of foam used is where the shoe gets it's cushioning from.



    While the Cumulus 21 provides cushioning and support for long distances, it doesn’t offer any bounce or responsiveness. I use my Cumulus 21’s for super long distances of 30+ kilometres when I want lots of foot protection and I don’t mind having a low cadence or minimal ground feel.


    Being a supportive neutral shoe like the Ghost, Pegasus and Wave Rider, the Cumulus 21 is also very stable.

    The midsole foams are not overly soft so there is no lean bias. I have flat feet and I pronate but the Cumulus 21 has plenty of support and never caused me any injuries or discomfort.



    The grooves on the outsole span the entire width of the forefoot, making the Cumulus 21 very flexible. Even though Asics has removed the plastic shank in the midfoot, the shoe still flexes in the correct place- in the front of the shoe.


    Outsole & durability

    There are two types of rubbers used in the outsole: AHAR (Asics High Abrasion Rubber) and Durasponge.

    The AHAR is the more durable material covering the high wear areas such as the heel. The Durasponge is made of softer, blown rubber which is lighter and has more road feel.



    The older Asics shoes were guilty of having hard outsole rubber lugs attached to much softer foam with a wide guidance line. The result was that you could feel the edges of the hard lugs through the shoe which was lumpy and uncomfortable.

    I’m glad Asics has fixed this issue by making the guidance line narrower and making the midsole softness more balanced throughout the entire midsole.

    After putting 50 miles on my pair, there is very little wear on the AHAR section with some slight wear on the Durasponge which lies under the ball of my foot.


    The Cumulus 21 feels like an exceptionally made shoe capable of going well over 800km. The luxurious upper and the well-constructed midsole show no signs of weakness.


    The non-Lite Show version of the Cumulus 21 has a smooth, compression-moulded insole. The Lite Show version has a blown Ortholite X-40 Sockliner which is softer and spongier than the regular compression-moulded one.

    This results in an overall softer-feeling ride. Ortholite insoles claim to have less than 5% compression over time ensuring you never lose cushioning while also being made from open-cell PU foam to allow air to circulate in and around the insole.

    I’m not sure why Asics decided to change the insole to Ortholite but it’s a change that I welcome because I prefer a softer ride with more protection for my delicate feet.



    The Cumulus 21 is a beefy workhorse capable of eating up many road miles. I had my reservations with Asics before running in the Cumulus 21 but now I understand why so many people are die-hard Asics fans.

    The Cumulus 21 has not only met my expectations but exceeded them. The Cumulus is now the first shoe I pick up for my long 3-hour plus weekend runs because I know that my feet will be well protected and the upper won’t give me any blisters.

    What sets the Cumulus apart from competitors in the neutral daily trainer category such as the Pegasus, Ghost and Wave Rider is that the Cumulus has an extra layer of underfoot softness making it more comfortable for super long runs.

    Following the releases of the Cumulus 21 and the well-received GlideRide, I get the feeling that Asics has turned a corner and will now produce hit after hit. I can’t wait to see the new releases Asics has in store for us in 2020.


    • Very smooth, stable ride
    • Highly padded midsole for ultra-long distances
    • Comfortable, luxurious upper
    • Exceptional build quality


    • No rebound or responsiveness in the midsole
    • FlyteFoam is heavy when compared to other modern super foams
  • 98 / 100 |

    Asics Gel Cumulus 21: Probably the best all-round shoe I’ve come across

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    So, I have been pleasantly surprised by this shoe. Many years ago, my running journey started with a set of Asics Kayano running shoes, and they were uncomfortable, they gave me blisters and were not the shoe to get me into running.

    Here we are days after completing Ironman Wales in the Asics Gel Cumulus 21 shoes, and I don’t have a single blister. My feet were well supported throughout the whole marathon, and they carried me on to a massive PB – top 25%.



    I have already ordered a second pair (since getting the shoes in early July), I’ve put over 300km on them. They’ve been comfy from the beginning without any breaking in period and became the shoe of choice for the Ironman very quickly.

    At this point, I have put lots of mileage into various Nike shoes, Hoka Cliftons, ON Cloud & Salomon. The Nikes are not perfect, but overall a good set of shoes (the Cliftons gave me nothing but blisters).

    The On Cloud trainers either had insufficient cushioning or were too heavy and gave me issues. The Asics, whilst not outstanding at any one thing, is an exceptional performer overall. Let me go into some details below.


    The outsole is quite grippy as the rubber is very soft. The sole is made from ‘Flyte foam,’ which is Asics’ latest technology making the sole soft and springy without being too heavy.



    On the rear inside part of the sole, the foam is also supported by a gel pocket, which contributes to the overall supportive ride. It also sounds stupid, but I’ve had no issues with stones getting stuck in the tread pattern.

    My only criticism of this shoe is that, after 300km, I’ve seen quite a lot of wear on the forefoot. However, it has not affected the performance of the shoe, and I have not suffered any loss of grip.


    The heel has good comfort and good stiffness. At the base of the heel, there is some padding, but as you rise up, the heel padding increases and the shoe design leans forward to give you that snug feeling. Overall, I suffered no heel slip whatsoever.



    There is clearly some support in the heel (low down reaching round to the sides) to give an extra level of support. On the heel, there is also a subtle reflective Asics logo for those night runs

    Upper & midsole

    The rest of the shoe is quite soft but still offers a level of support. The support is reduced from halfway down the laces to the toe box to keep feet cool.



    There is also quite a cool design to the front of the shoe where the holes in the outer layer let through a color underneath. I liked this!

    On our outside of the shoe is an Asics logo, which also has a reflective center and a pretty cool pattern. The Asics logo also has the ‘Gel Cumulus’ within it.

    Tongue & laces

    The Gel Cumulus 21 has quite a padded tongue with a loop near the top to hold the position relative to the laces. The loop also has ‘21’ on it denoting the model.

    The tongue isn’t elasticated in any way, just tied down at the base. I do like the tongue’s, which are elastically constrained to the side of the shoe as it gives you a really nice snugness. Maybe this is a feature that could exist on the 22’s.



    The laces are normal – but a good length. It sounds stupid, but with some shoes I have, the laces are long, and on others, they’re barely long enough. On the Asics, they’re the perfect length.

    Once tied in a double bow, there is now flapping during running. On my longest runs, I did suffer a small amount of tongue slippage but nothing that caused me any irritation.

    Also worth noting, the lace loop holes are reinforced to protect both your feet and the lift of the shoe.


    Standard, simple, but effective Asics insole is used here. I suffered no blisters or any chafing with this insole from the very beginning and, even on the longer runs, suffered no issues.

    In the past, running in Hoka’s, I suffered sharp pains in my toes after the hour mark. In the Gel Cumulus, they were comfy for every kilometer!



    The grip on these shoes has actually been a massive pro point for me. Training for Ironman.



    Wales meant that I needed to do a lot of hill running, and these shoes gave me grip on the ups and stopped me slipping on the downs. After 300km, the grip on the forefoot has started to fade, but I haven’t started to suffer yet as a result.

    Other notable features

    I ordered the Mako blue/white version of the 21’s, and I was really pleased. The read-through of the orange underlayer around the front of the shoe gives a really cool effect.



    These are on the normal side of weight. They aren’t particularly heavy, but they aren’t particularly lightweight.

    For me, heavy trainers hurt my heels if I accidentally catch them. However, these are the perfect weight to give you comfort without any pain. My shoes came in at 333g per shoe for a size 10.5.


    I ordered the same size as Nike, ON, and Hoka, so, in my opinion, they are true to size. No rubbing or chafing whatsoever.


    This shoe was an absolute Godsend. After 3-4 runs, I knew they were the shoe for the Ironman. They are true to their name that the shoe is designed for running further.



    It’s not a quick shoe, but it will support you up to marathon level without major issues. I’m sure I could PB in these too as the foot pain is minimal irrespective of distance.

    They’re not the lightest and not the cheapest, but if anyone is looking for a shoe capable of delivering easy 5k runs through to comfortable marathon shoes, look no further. I plan to step up to ultra-distance soon, and this is exactly what I will start with.

    If you’re after a distance shoe – buy this one. It is excellent. As mentioned earlier, the next set is already on order!

  • 87 / 100 | Road Trail Run | | Level 5 expert

    It's an option for those who want some solid, durable performance.

  • 90 / 100 | Mark Wood | Level 3 expert

    From the 20 to the 21 of the Cumulus, they did a great job making this just feel fantastic when you step into this shoe.

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  • The successor to the popular Asics running shoe, the Gel Cumulus 20, has now been made even better. The Asics Gel Cumulus 21 features an even more improved level of comfort and support by integrating Asics’ innovative technologies in this neutral running shoe that will cater to everything that any runner needs.
  • The Gel Cumulus 21 has now added the use of the FlyteFoam Propel technology.  This technology combines a lightweight foam formulation with a high-energy return elastomer for increased bounce and unparalleled toe-off that offers a better performance in every stride.
  • This 21st version of the Gel Cumulus also features the Impact Guidance System which combines interlinked sets of technical features that work together for more natural foot movements during the run.
  • Also found in this shoe is the more refined stretchable Jacquard mesh upper which has been modified for enhanced breathability, comfort, and fit. It now has enough perforations that allow efficient airflow, thus keeping the foot cool and dry.
  • The ComfortDry Sockliner is also incorporated in this shoe. It helps regulate the overall shoe temperature with its unique dual-layer cushioning system that combines the support of the base foam with the slow recovery foam for a more customized insole.
  • Even more updates to the Gel Cumulus 21 are showcased in the shoe’s midsole with the Rearfoot and Forefoot Gel cushioning system.  It is the technology responsible for the shoe’s premium shock absorption and cushioning.
  • And last but not least is the improved function of the FluidRide technology. This exceptional shoe tech is a weight reduced two-layered sole that gives the shoe its improved cushioning and incredible bounce.

The Gel Cumulus 21 comes in medium size D for men and medium size B for women. This neutral Asics road running shoe’s base fits those who have the standard medium sized heel. Also with the sizing of this shoe, going a half size higher than one’s actual size will ensure that the shoe will not be too tight when worn.

Similar to the well-known Asics Gel Quantum 180 4, the outsole of the Gel Cumulus 21 is made of the light AHAR sponge rubber outsole. The AHAR is an acronym for Asics High Abrasion Rubber, and it provides excellent abrasion resistance,  and traction. It is placed in critical areas of the outsole to provide exceptional durability.

Meanwhile, found in the shoe’s forefoot is the DuraSponge outsole material which is a blown AHAR rubber that enhances both the cushioning and durability in the forefoot. The DuraSponge also functions as a shock absorber throughout the run, making the ride more enjoyable than ever.

The midsole area of the Gel Cumulus 21 is packed with the most innovative Asics technology. It features the reduced weight FluidRide® which provides the right combination of bounce back, durability, and cushioning.

The shoe also uses the FLYTEFOAM™ Propel technology which is Asics’ energetic foam formulation that provides excellent bounce and energy return. This midsole technology is made of a unique elastomer compound that offers great responsiveness no matter the duration of the run.  It also utilizes organic super fibers that help lessen packing out the that usually happens with softer, low-density foams.

The use of Asics midsole technology continues with the SPEVA™ foam in the Gel Cumulus 21. The SPEVA™ foam is a spongy layer between the sole and upper designed to absorb shock and improve the shoe’s cushioning performance.

Also adding to the shoe’s midsole power is the I.G.S® or better known as the Impact Guidance System technology.  This midsole technology is based on Asics’ design philosophy which is they aim to complement and not change the natural movement of the legs and feet. It combines four different types of technology for the cleanest stride possible. An external heel counter minimizes ankle movement while Trusstic technology keeps your foot in place and aids in smoother landings. The Guidance Line technology also increases stability, and the DuoMax technology dynamically reduces stress and evens the foot plane.

Completing the Gel Cumulus 21’s technology-packed midsole are the Rearfoot GEL™ and the SoLyte Midsole. The Rearfoot GEL™ technology is responsible for attenuating the shock received during toe-off phases, while the SoLyte Midsole which also has a tough material called AHAR+ provides exceptional grip and helps improve the shoe’s durability and cushioning.

The Gel Cumulus 21 is now engineered with the stretchable Jacquard mesh upper which provides the shoe’s breathability, flexibility, and customized fit. The mesh’s elasticity is multidirectional, thus providing freedom of movement. It is also reinforced in strategic areas to offer more support to the shoe.

The shoe also has a reflectivity feature which contains reflective materials designed to enhance better visibility during low-light hours. This enhancement guarantees the runner’s safety while training at any time of the day.

Besides the use of the new jacquard mesh, the shoe’s upper is also covered with the ComfortDry.  It is an anti-bacterial material that creates a cooler, drier, and healthier shoe environment while running for long hours.

The shoe also features the Discrete Eyelets which are independently placed eyelets that aids in dispersing lace tension caused by tightened laces through a single eyelet.  With the use of the Discrete Eyelets, it creates a customized fit feeling resulting in better upper comfort.

Finally finishing off the shoe’s upper is the Seamless Construction,  it reduces the chances for irritation and friction brought by traditional stitches and seams.

Jens Jakob Andersen
Jens Jakob Andersen

Jens Jakob is a fan of short distances with a 5K PR at 15:58 minutes. Based on 35 million race results, he's among the fastest 0.2% runners. Jens Jakob previously owned a running store, when he was also a competitive runner. His work is regularly featured in The New York Times, Washington Post, BBC and the likes as well as peer-reviewed journals. Finally, he has been a guest on +30 podcasts on running.