ASICS GEL-Kayano 21 vs. 20 review

Learn about the differences and similarities between ASICS GEL-Kayano 21 and ASICS GEL-Kayano 20 to find out which running shoe is better for you.

NEW! ASICS GEL-Kayano 23 vs. ASICS GEL-Kayano 22 and ASICS GEL-Kayano 23 vs. ASICS GEL-Kayano 24 and ASICS GEL-Kayano 24 vs. ASICS GEL-Kayano 25

The ASICS GEL-Kayano 21 is the updated version of the ASICS GEL-Kayano 20, so naturally these two ASICS running shoes should not differ that much and if anything, the running shoe technologies used should be better.

The GEL-Kayano is a top-of-the-line ASICS stability running shoe for runners who exhibit a mild to moderate degree of overpronation.

ASICS claims that the ASICS GEL-Kayano 21 has a more comfortable and secure upper than the ASICS GEL-Kayano 20. The reason for this is that they improved the FluidFit technology in the upper.

And indeed, when looking at the upper, it is clearly visible that the FluidFit overlays have been distributed more sparingly, efficiently, and discreetly around the forefoot.

And those overlays that were on the lateral side coming over the midfoot, have been removed from the Kayano 21 and replaced by normal synthetic overlays.

This means that your feet should not feel as "smothered" as they probably would have felt in the Kayano 20. The ASICS GEL-Kayano 21 should provide more looseness and comfort in the toe box.

The second thing that ASICS says it improved is the heel construction. In the ASICS GEL-Kayano 20, the outer heel support went across the Achilles tendon, while it follows the line of the Achilles tendon in the ASICS GEL-Kayano 21.

I can see where this might feel a bit more comfortable, however, it remains a matter of personal preference.

The third change when going from the ASICS GEL-Kayano 20 to the ASICS GEL-Kayano 21 is the sockliner. The ASICS GEL-Kayano 21 has an ortholite X-40 sockliner in it that is light and should provide you with more rebound, breathability, and dryness.

Other than that, both running shoes still make use of the common ASICS running shoe technologies such as FluidRide for bounce back and cushioning, the Impact Guidance System (IGS) for enhancing your gait, Dynamic DuoMax for support and stability, an extra gender-specific cushioning layer in the midsole for women, and GEL cushioning in both the forefoot and rearfoot.

Note however that because the ASICS GEL-Kayano 21 makes use of a newer FluidRide midsole technology and a slightly different midsole design, it turns out to be much more cushy than the ASICS GEL-Kayano 20, especially in the heel of the men's version of the shoe. The difference in cushioning in the women's versions of the shoes is minimal.

So on these fronts, the ASICS GEL-Kayano 21 does not differ much from the ASICS GEL-Kayano 20. Having said that, though, ASICS was a bit sneaky to change the layout of the rubber compartments on the outsole of the Kayano 21.

This also goes for how the Guidance Line that runs in the outsole of the Kayano 21 compared to the Kayano 20.

In the ASICS GEL-Kayano 21, there are more flex grooves especially under the medial side of the forefoot, meaning that you should get a bit more flexibility during the toe-off phase. However, running shoe lab tests have shown that the ASICS GEL-Kayano 20 is still overall more flexible than the ASICS GEL-Kayano 21.

And the high-abrasion rubber lug at the back of the foot under the heel has been reduced a bit in size, but now covers a larger area around the heel than it did in the ASICS GEL-Kayano 20. This means that the ASICS GEL-Kayano 21 should appeal to a much larger group of heel-strikers.

In addition, the rubber lugs under the heel are a bit more segmented in the GEL-Kayano 21, especially on the outside of the heel.

All in all, this should give you better shock absorption if you tend to land on the outsides of your heels, but do keep in mind that the Kayano 21 might feel different than the Kayano 20 on heel-strike due to the slight change in rubber lug placement.

The women's versions of the ASICS GEL-Kayano 20 and the ASICS GEL-Kayano 21 both weigh approximately 9.5 oz (269 grams). The men's versions of the running shoes weigh about 11.2 oz (318 grams) and 11.3 oz (320 grams) with the ASICS GEL-Kayano 21 being the slightly heavier one.

Making a choice between the ASICS GEL-Kayano 21 and the ASICS GEL-Kayano 20 should not be that difficult. The price is the same, the Kayano 21 has not changed much overall compared to the Kayano 20, but you have a better and more comfortable running shoe in the ASICS GEL-Kayano 21 with the improved FluidFit, cushioning, and sockliner.

Note: The weight of a running shoe depends on the size of the running shoe, so any weights mentioned in this review may differ from the weight of the running shoe you choose to wear. Running shoes of the same size were compared for this review.

The two links above will take you to where you can read more about the running shoes.

This review falls under: ASICS

Disclaimer: This running shoe review on is based on personal research and analysis of data that has been made publicly available by running shoe manufacturers and other companies that are dedicated to serving runners, and is not claimed to be accurate, complete, or up to date. While the information presented in this review is intended to help you better understand the differences between running shoes, we shall not be held liable for any purchasing decisions you make based on this information. Please use your own good judgment before making a purchase. The owner of this website receives a small compensation whenever you buy a product after clicking a product link on this website. Read our full disclaimer and privacy policy.