adidas Ultra Boost 21 Review

Out of the box and ready to launch—the adidas Ultra Boost 21 requires no breaking in. A sock-like fit with a lace closure gives my feet a little more breathing room in the toe box, though it may border on too roomy for those with narrower feet. Boost capsules in the midsole give this shoe a bouncy energy return, while Boost cushioning helps deliver soft landings. The Ultra Boost 21 is a perfect daily trainer for the road or the gym.

This brand never fails to deliver a stylish shoe, and the Ultra Boost 21 is no exception. The fit of the 21st rendition is a bit wider than previous versions and does not hug my feet quite as snugly. I usually prefer a more locked-in and structured upper fit, but those with wider feet will likely enjoy this updated feel.

In terms of performance, the Ultra Boost 21 is not very propulsive and didn't give me the level of responsiveness that I wanted to pick up the pace. The shoe is also pretty heavy for a daily trainer, and I felt like it was weighing me down during my longer runs. The Ultra Boost 21 has been updated with a higher stack height, but unfortunately, it has lost some of the cloudlike underfoot feel of previous versions. I am also a midfoot striker and thought that there was way too much padding in the heel for me. The additional stack height felt restrictive, but heel strikers will not be bothered by this. To wrap things up, the Ultra Boost 21 is not my favourite update, but this shoe is still a great daily training option for runners looking for reliable comfort for slower-paced runs or recovery efforts.

I wore the original Ultra Boost and quite liked that shoe. It was a bit ahead of its time with the responsive Boost foam midsole. When I received version 21, I was excited to see how the shoe had changed over the years, especially considering six years have now passed since the original first hit markets. Unfortunately, I am sad to report that the Ultra Boost 21 seems dated. In many ways, the shoe hasn't changed from the original version and still has a snug fit with a shallow toe box, a stupid midfoot cage for the lacing, and a highly responsive cushioning system. More Boost has been added, but that comes with increased weight as a penalty.

The shoe doesn't feel much more cushioned than the original. With shoes like the Saucony Endorphin Speed, Skechers GoRun Max Road 4+ Hyper, and Nike ZoomX Invincible Run all proving it's possible to have highly cushioned, highly responsive shoes without adding any weight, it makes me wonder how the Ultra Boost 21 is relevant today. There are shoes like the Brooks Glycerin and ASICS Nimbus that are highly cushioned but not very responsive. However, those shoes feel better for cruising, because they don't have the weight penalty of the Ultra Boost 21. I think adidas should look at the Saucony Triumph 18 to see a shoe that realises the potential of the Ultra Boost.

All that being said, the adidas Ultra Boost 21 is an adequate shoe for a heavy heel-striker and for runs lasting up to an hour or so.