Brooks Adrenaline GTS 25 vs Glycerin Flex

The Brooks Glycerin Flex and Brooks Adrenaline GTS 25 sit on opposite ends of the daily-trainer spectrum, targeting runners who want very different things from their shoe. The Adrenaline is a stability trainer designed for guidance and correction, using support features that help manage overpronation and keep your stride aligned. The Brooks Glycerin Flex is built for the opposite philosophy, prioritizing freedom and a more natural, uninhibited transition, using a highly flexible, decoupled midsole design that bends easily and feels less corrective. Despite those different intents, both can feel similarly stable laterally, but the Adrenaline adds corrective support while the Flex relies more on its inherent geometry. The Flex also feels more cushioned overall and has a bit of a lower drop, even if both shoes feature very high drops.