Brooks Glycerin 22 vs Brooks Glycerin Flex:
Which to Choose

Start with what they share: nitrogen-infused DNA Tuned foam, no plate, a neutral platform, and a happy pace band of roughly 5:30–6:30 min/km for easy and steady miles. The differences are in structure and weight. The Glycerin 22 is the taller, more substantial shoe — a stack of about 38mm and a 10mm drop, weighing around 289g in a men's US 9 — and it delivers plushness through a wide, sidewall-supported, comparatively stiff base that keeps transitions composed and predictable. The Glycerin Flex takes the opposite approach to comfort: a lower platform (roughly 35mm heel / 26mm forefoot), a slightly lower drop, and about 264g on the foot, with deep flex grooves and a more segmented forefoot that let the shoe bend and move with your stride for a fluid, ground-connected feel. In practice the 22 feels firmer through the midfoot and more overtly protective, trading some natural motion for stability and stack; the Flex feels softer and more forgiving underfoot but more damped, giving up a touch of the 22's steadiness for flexibility and a lighter, more natural gait. Responsiveness is modest on both — neither returns real pop when you try to accelerate — and the 22 rates a step higher on cushioning, responsiveness, and stability in our metrics, which matches its taller, more structured build. On distance, both cover 10K and the half comfortably at relaxed efforts; the 22's extra stack and support give it a genuine edge for stepping up to the marathon and long, high-mileage weeks.