The Asics Gel-Cumulus 21 Is a Supportive, Durable Trainer

The latest Cumulus gets a modest update to the upper, but it’s still one of the most adaptable shoes in the neutral category.

The RW Takeaway: The Gel-Cumulus 21 is a substantive shoe for neutral runners who prefer comfort and support over lightness.

  • A two-layer foam midsole with heel gel cushioning soaks up impact forces
  • The engineered mesh upper holds your foot in place, but the added padding around the collar and tongue made testers’ feet run hot
  • A high-abrasion blown rubber outsole showed little wear after 100 miles

Price: $180
Weight: 289 g (M), 226 g(W)
Type: Road



The new Asics Gel-Cumulus 21 sports a few modest updates over the previous shoe. The sockliner has been recontoured to better match the shape of the foot; and the collar has even more foam padding for a more comfortable fit. The entire upper uses a new last that’s taller in the toe box and forefoot. Lastly, the shoe’s FlyteFoam Lyte, the white foam on the bottom of the two-layer midsole, has been made softer for easier landings. And because it’s an Asics, you still get a wedge of gel padding in the crash pad.

The ride is supportive and stable, our testers said, although the Gel-Cumulus 21 might feel bulky for runners accustomed to flexible and lightweight trainers. The Guidance Line that runs the length of the shoe adds torsional stiffness, making this neutral trainer feel sturdy throughout your pronation. Our testers loved the grip from the high-abrasion, blown rubber outsole, and noted that it showed almost no wear after a month of running. With moderate cushioning and a solid, stiff construction, the Gel-Cumulus 21 is ideal for runners who want supportive cushioning that outlasts the competition.


Gel-Cumulus 21
  • Two-layer midsole provides supportive cushioning
  • Well-padded upper keeps your foot secure


  • Heavy, not very flexible

A Stiff, Substantial Midsole

The blue foam, just below the upper, is Asics’s FlyteFoam Propel, an elastomer blend designed for high rebound. The white foam below it is FlyteFoam Lite, a lighter compound.

The Gel-Cumulus 21 midsole is quintessentially Asics: It’s stiff but well-cushioned, with two layers of foam and a sliver of Gel on the lateral side of the heel, the latter material meant to provide a smooth transition as your foot touches down. The two-part midsole puts the bouncier FlyteFoam Propel beneath your foot, giving you a high-rebound sensation while the (FlyteFoam Lyte) EVA foam below it adds lightweight cushioning.

Despite having four horizontal flex grooves in the forefoot and a vertical groove that decouples the lateral and medial sides of the shoe (Asics calls it the Guidance Line), the Gel-Cumulus 21 isn’t that flexible. “I felt like I was running with blocks on my feet,” said one tester. Asics shoes can be polarizing like that; other testers lauded the shoe’s supportive cushioning. “The cushioning is perfect for heel strikers, with less cushioning from the midfoot forward,” said another tester, who noted that her knees felt better in the stiff Gel-Cumulus 21 than they did in a soft pair of Hoka One Ones.

Supportive Mesh Upper

The heel counter is completely stiff, holding your foot in place while padding around the ankle collar keeps you comfortable.

The Gel-Cumulus 21 gets a new upper, although you’d be forgiven for not noticing. The two-layer engineered mesh material looks similar to the old shoe, although whereas the old shoe’s mesh wrapped around the entire shoe, the new shoe has mesh only at the forefoot. Designed to breathe, the two-layer mesh still traps more heat on hot days than do lighter, single-layer mesh uppers. The toe box was wide enough for most testers’ feet.

Behind the Asics logo, the upper stiffens up, with TPU elements supporting a tightly woven synthetic material that’s completely firm once you reach the heel cup. The ankle collar and tongue are lined with thick foam for comfort, and testers generally liked the stiff yet padded design. “The hard and sturdy heel counters gave much-needed support on uneven surfaces, well worth the extra weight,” said one tester. Asics hasn’t joined the trend of ultra-minimal, weight-saving uppers, and the weight penalty makes for a luxurious construction that almost all of our testers appreciated.

Tough Rubber Outsole

Blown rubber covers the shoe’s entire outsole; flex grooves split up the rubber patches and allow the shoe to flex—although it’s still not particularly flexible.

Excluding the flex grooves, there’s blown rubber beneath the entire shoe—no exposed foam here. Asics’s used blown rubber for this high-abrasion formula; it’s not as hard as high-abrasion carbon rubber, but still exhibited excellent durability during testing. “These look as good as new after 100 miles of wear,” said one tester. We also found reliable on-road traction from the rectangular treads, never losing grip on wet and muddy pavement.

What One Tester Said

Tiffany V., tester since 2019
Arch: Flat | Pronation: Neutral | Footstrike: Midfoot

“One of the best features: The thick sole throughout the entire shoe. It created a nice spring [sensation] and comfort on the road. The sole had high durability; you could barely feel your foot striking the road due to all of the extra cushioning. I felt as though the extra cushioning added to the bulky feel of the shoe. They were adequate for short runs and speedwork. I prefer a lighter-weight shoe and would recommend these for someone seeking stability and added cushioning, even though the tongue of the shoe is a little thicker than most.”


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