Brooks Glycerin 23 and GTS 23 Deliver Comfortable, Flexible Running Shoes for All Gaits Brook's latest Glycerin 23 and its stability variant, the GTS 23, combine DNA‑Tuned cushioning, a breathable knit upper, and subtle guide rails to provide a supportive yet roomy ride. The shoes have won over both neutral and overpronating testers for their comfort, lightweight construction, and effective stability system that does not feel intrusive. Testers praised the roomy toebox, slippage‑free fit, and temperature control even in hot conditions, making these models well suited as daily trainers for runners with bunions, swelling, or seeking extra toe room. Brooks has continued to push the envelope in its Glycerin line with the release of the Glycerin 23 and its stability counterpart, the GTS 23. Both shoes have been the subject of extensive in‑field testing by the brand's own staff and independent reviewers, and the results have been overwhelmingly positive across a variety of foot types and running conditions. The GTS 23 was developed to provide the same soft, responsive feel of the neutral Glycerin 23, but with added guidance for runners who need a little extra stop‑gap stability without the bulk of older stability models.For anyone who has ever been skeptical about stepping onto a stability shoe and ending up feeling like the entire ankle is tethered into a rigid brace, the GTS 23 takes a different approach: it inserts thin, firm foam "guide rails" along the medial and lateral edges of the heel. These rails are designed to keep the knee and foot aligned when your form goes haywire, but they do not act as a rigid chassis.In fact, the rails are barely noticed by neutral‑gait runners, while for overpronators they provide a subtle, reassuring buttress that keeps the foot from rolling too far inward. The net result is that the GTS 23 feels as responsive and cushioned as the neutral model, with barely a single ounce of added weight. The DNA‑Tuned cushioning layer has been a major selling point for the Glycerin line, and the 23 models continue to build on that.DNA‑Tuned is a newer iteration of the foam that first appeared as DNA Loft v3, and it improves both softness and responsiveness. The footbed is engineered with larger cells in the heel for a softer landing, and progressively smaller cells toward the forefoot so that the mid‑toe remains responsive.The GTS 23 adds a little more in the forefoot-about two millimetres-so it feels a bit stiffer during the first couple of training sessions, but after a short break‑in period it becomes just as supple as the neutral shoe. This subtle difference is especially beneficial to mid‑foot strikers, who tend to appreciate a slightly firmer foothold. The cushioning is never at the expense of durability; the foam maintains its resilience over thousands of miles.Fit is always a key concern for runners with foot issues such as bunions or swelling, and the Glycerin 23 and GTS 23 are hailed for their roomy toebox. The "engineered knit" upper is knit in an area that's mindful of the forefoot and ankle, creating a snug yet flexible fit that prevents the foot from sliding in the heel or feeling sealed into an uncomfortable tightness.In comparative tests against popular competitors such as the Ghost 18 and the Saucony Endorphin Speed 4, the Glycerin line offered enough clearance around the toe area to accommodate larger feet, and even a size 12 with an enlarged forefoot could find its space without getting crammed. Because the upper's knit material is breathable, the shoe also performed well in heat; reviewers reported that they ran in the GTS 23 at temperatures above 85 degrees Celsius without any blisters or overheating, a stark contrast to some other models that tend to develop sore patches on the toes.The stability "GuideRails" feature in the GTS 23 has been noted for its practical benefits. One neutral‑gait tester recounted how the Rails helped maintain proper alignment during a late‑stage run when fatigue could have thrown the form off. Another reviewer-who regularly runs with mild overpronation-found that the Rails not only corrected misalignments but also eliminated early notes of knee and ankle discomfort that had persisted for weeks.What is most impressive is that the weight penalty, while present, is negligible: the neutral Glycerin 23 weighs 8.8 ounces, while the GTS 23 weighs 8.9 ounces for a women's 6.5. That minute difference didn't translate into a perceptible difference in running feel-run feeling words are hard to distinguish when two shoes are that close. Because the Glycerin 23 and GTS 23 share almost every element-same upper construction, same DNA‑Tuned midsole, same total length-the differences are almost purely functional.The GTS 23's guide rails, though small, provide a level of stability that is especially attractive to runners who either need it or simply want the safety net of extra guidance. The shoes are ideal for everyday training, long runs, and anyone looking for a dependable, comfortable trainer that keeps the toe area roomy and the midsole responsive.In short, whether you're neutral or a mild overpronator, the Glycerin 23 and GTS 23 give you a shoe that feels natural, supportive, and ready to go every day