Brooks Adrenaline GTS 25 vs Brooks Glycerin GTS 23:
Which to Choose

Both shoes share a 10mm heel-to-toe offset, GuideRails guidance for mild-to-moderate overpronation, and a plate-free, nitrogen-infused midsole, so they feel like cousins underfoot rather than opposites. The differences are in cushioning and mass. The Glycerin runs a taller 38mm heel / 28mm forefoot stack of DNA Tuned dual-cell foam that lands plush and pillowy, with a slightly firmer push at toe-off; the Adrenaline sits lower at 36mm / 26mm on DNA Loft v3, which reads as forgiving and mildly soft rather than pillowy — more planted and firm, less deep and cushy. That extra foam costs the Glycerin weight: it comes in around 306g (men's US 9) versus roughly 295g for the Adrenaline, so the Adrenaline feels the marginally more nimble and honest of the two, while the Glycerin trades a little agility for plushness. On paper the Glycerin scores a touch higher on cushioning (5/6 vs 4/6) and responsiveness (4/6 vs 3/6), but neither is snappy — both go vague and heavy if you push hard, and both top out around 4:45–5:00 min/km. The most practical split is range: the Adrenaline is comfortable through 10K, half, and full marathon distance at a steady effort, while the Glycerin is happiest on easy and long training runs and caps out at the half. Neither is a tempo or race tool.