Brooks knows a thing or two about making running shoes, having been in the game since 1914. The Glycerin series offers a well-sustained, cushioned ride, perfect for long runs. of roads, but without making the shoe too heavy.
Our reviewer is a fan of high rebound and a thick, bouncy sole, and the Glycerin 21 ticked all of their boxes, quickly becoming a firm favourite. Having already tested the Ghost 15 and Ghost 16 and not going further with them, the Glycerin 21 was a great reference for Brooks in the eyes of our reviewer.
Brooks Glycerin 21: How we tested it
Brooks Glycerin 21: Build and fold (Image credit: Future/Lou Mudge)
Our reviewer first tested these shoes a few months ago and has been using them for trail running and treadmill work. Our tester covered more than 50km in these shoes, mostly on slow, long runs.