Updates to Asics Gel Cumulus 20 SP

  • The Asics Gel Cumulus 20 SP was designed with the I.G.S Technology. It stands for Impact Guidance System, and it is a design philosophy that makes use of linked componentry to enhance the foot’s natural gait.
  • On the midsole is the FlyteFoam which was developed in the Asics Institute of Sports Science. It is approximately 55% lighter than standard industry foams. It delivers a bounce that comes from organic “super fibers” that bounce back to their original shape when the weight is lifted from the shoe’s platform.
  • To enhance the shock attenuation delivered by the midsole, two gels were added one the forefoot and rearfoot areas of the platform. These cushioning gel pads also allow movement in multiple planes, permitting the foot to transition smoothly from one phase of the running cycle to the next.
  • AHAR rubber, which is also used in the Cumulus 20, was placed on areas on the outsole that need the most protection. More specifically, this rubber was placed on areas that wear out quickly because it is highly durable. 

Size and fit

The Asics Gel Cumulus 20 SP comes in standard running shoe sizes. Runners who wish to procure a pair can make use of their usual running shoe measurements. The same goes for this shoe’s width. It is available in medium measurements – B – medium and D – medium for women and men respectively.


The outsole of the Asics Gel Cumulus 20 SP is made up of two types of rubber. The first one is the AHAR Rubber. Its name is an abbreviation for Asics High Abrasion Rubber. It is exceptionally durable, which is why it was placed on high-wear areas. Meanwhile, the forefoot is covered with the DuraSponge – blown AHAR rubber – for cushioning and durability.

To make moving easier, the rubber materials were separated into sections by flex lines. This design allows the outsole to move together with the shoe to deliver a movement that doesn’t feel hindered or restricted.


The midsole has been designed with the I.G.S or Impact Guidance System Technology. It is a design philosophy that links components together to allow a more natural gait transition throughout the running phase. It’s not just one feature functioning, but a link between interdependent parts to produce optimal movement of the foot.

Providing a bounce back to the runner’s every stride is the FlyteFoam Midsole Technology. With the use of organic fibers that bounces back into its original shape in the space of each stride. This mechanism provides an adaptive cushioning throughout the run.

Another component of the midsole is called FluidRide which provides the right combination of cushioning and responsiveness on w reduced weight. All of these benefits while also delivering durability.

The Forefoot and Rearfoot Gel Technology Cushioning System were added to the midsole. Imagine two gel pods on the mentioned areas on the platform. Primarily, these components aid in shock attenuation and allow proper movement of the foot throughout the running cycle.

At the bottom of the midsole, visible on the outsole, is a Guidance Line Technology. It sections off the midsole into segments. The primary objective of the Guidance Line is to enhance the efficiency of a runner’s gait.


The upper was made with the SPEVA 45 last. This is lasting that has a density of 45, which provides a high cushion and an improved, comfortable feel from within.

The material that makes up this part of the shoe is called jacquard mesh. It’s a type of mesh that’s durable and comfortable. It hugs the foot in all the right areas. It’s also anti-static, shrink-resistant, and anti-crease – benefits that will come in handy in a running shoe.

The upper of this Asics shoe was designed to have a seamless construction. Because of the absence of the usual seams and stitches, the potential for irritation is significantly reduced. The smooth upper also gives the shoe a more modern look.

For better visibility during low-light conditions, the upper was made to reflect light. When runners run at night, the shoe will appear as if it is lighting up.

Inside, an Ortholite Sockliner was added. This insole is specially designed to fight off bacteria that cause foot odor. It also sufficiently absorbs foot sweat, so the inside environment of the shoe is kept dry and ideal. Because it is an extra insert, it enhances the comfort underfoot and provides additional cushioning to the runner.


How Asics Gel Cumulus 20 SP ranks compared to all other shoes
Bottom 18% road running shoes
All road running shoes
Bottom 23% Asics running shoes
All Asics running shoes
Bottom 19% neutral running shoes
All neutral running shoes


The current trend of Asics Gel Cumulus 20 SP.
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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.