The shoe hugged my foot nicely, with a super cozy upper, moderate but noticeable arch support, and a really comfortable padded heel counter with no slip issues.

One aspect of the shoe I liked was the width. It isn’t a tailored fit but it gives your feet room to feel and splay out naturally. This natural feeling is extended to the engineered mesh because of its flexibility. The Adrenaline is built on tried and true technologies Brooks has tweaked every few years. The Adrenaline and its neutral counterpart the Ghost are Brooks best selling trainers. Saying this, it still felt pretty soft, nicely responsive, and only got better the more miles I ran. The firmness was definitely noticeable at first, but after a few runs, I found that the foam broke in nicely, becoming more supple.

However similar to the other issues that I experienced with this shoe, the breathability issue seemed to disappear as I wore the shoe in. The toe box also feels more comfortable now after a few miles, although I’d still prefer a bit more room for my toes to splay. The Landing

It is an adaptive system and only engages when you need support. This change was monumental at the time but now three years in and it is the norm. Segmented crash pad flexes with the foot, offering customized cushioning and stability for a smooth heel-to-toe transition. Believing that the ‘correct’ way to run is simply your natural way, Brooks developed their Guiderail technology to support those with a tendency to overpronation and heel strikers, hoping to keep them safe from injury whilst allowing them to keep running in their own way. For a road running shoe, I was pretty impressed with how the Adrenaline GTS 21 performed in all these environments, proving to be much more versatile than I was expecting.

Brooks Adrenaline GTS 21Sole Unit

The drop of this shoe is 12mm, being 1mm less than the previous GTS 20, but still much higher than the running shoe average drop of 8-10mm. The upper of the Adrenaline aided in providing stability. The heel counter is a strength of the upper. It was cushioned and held my feet in place. I joked with my running friends that they are my “dad shoes” because they look like a pair my dad would wear along with me now being the father of two little ones.