Brooks Glycerin GTS 22 Vs GTS 23 – Small Changes, Big Impact

Design

Upper

The Glycerin GTS 23 features a new triple-jacquard engineered upper for an even better fit. The triple-knit design has a 3D-like mesh upper that provides a little extra padding around the foot while remaining breathable.

The fit is now a little more precise. It hugs the foot, and there’s no hint of ‘bagginess’.

Midsole

The new Glycerin GTS 23 gets a higher stack midsole cushioning. There is now an additional 2mm of DNA Tuned foam in the forefoot. While this doesn’t sound much, it does have a big impact, giving the shoe a much softer and indeed, responsive feel and toe-off.

There’s no mention of a reformulation of the midsole by Brooks, but the whole shoe feels a little softer.

The geometry of the midsole has been tweaked a little, too. The lateral side wall is more concave, and the medial side wall is a little more convex, sitting a little prouder. These small changes, along with the lower heel-to-toe drop, give the shoe a more balanced ride and aid the overall stability.

Outsole

There’s a new outsole pattern to the Glycerin GTS 23. It’s by no means a big change, and to many runners it may go largely unnoticed. The pattern features a more ribbed texture and feels a little softer. I think this makes the shoe a little more flexible, particularly in the forefoot, even with the additional depth of cushioning.

Fit

The fit of the new Glycerin GTS 23 is as good as ever. I have gone true to size, but must admit, around 50% of runners that I have fitted with the shoes have gone up a half size. So, try before you buy if you can.

The new triple-jacquard mesh feels a little snugger around the foot, and there’s a little less volume in the forefoot, but for me, it fits and feels great.

Weight

The new Glycerin GTS 23 has put on a little weight over its predecessor, the 2mm increase in the forefoot stack height no doubt accounting for most of this. But it is only around a 3% increase, so hardly noticeable, and when the shoe is on the foot, the improvement in fit means there’s no noticeable difference.

Heel Drop

Increasing just the forefoot cushioning by 2mm means the shoe now has a 2mm lower heel-toe drop. When running, the small difference isn’t really noticeable, especially given the soft nature of the heel cushioning, but the shoe now actually feels better and more balanced for the change.

How's the Ride?

The Glycerin GTS 23 refines the run experience thanks to the additional 2 mm cushioning in the forefoot and lower drop.

The heel-to-toe transition feels smoother, softer and a little more responsive.

With only the additional forefoot cushioning changing the GTS 23 over the GTS 22, the shoes really does feel transformed. The GuideRails seem more efficient at providing control. Perhaps this is thanks to the slightly lower heel drop. The foot sits within the rearfoot cushioning and feels supported and very well balanced.

The GuideRails are still the same configuration as in the previous model, and while Brooks is shifting towards referencing them as ‘GuideRail Technology System’, they are exactly the same as the ‘Go-to-support’ design.

GuideRails are small ‘extensions’ of midsole cushioning on both the lateral and medial sides of the rearfoot cushioning. As the heel strikes the ground on the lateral side of the heel, the GuideRail helps prevent the foot from supinating. As the foot naturally pronates inwards, any excessive roll is reduced by the medial GuideRail. Support and control are effective and efficient, feel natural and work for a wide range of runners with varying needs.

The overriding feel of the Glycerin GTS 23 is one of smooth cushioning, gentle stability and effortless ride. Long runs feel supremely comfortable, and faster efforts are taken in your stride easily and with a smooth transition.

The shoe is still less than a month old, so I only have around 100 miles on the clock, but so far, the durability seems every bit as good as the Glycerin GTS 22 proved to be. This shoe should see more than 500 miles of training logged with ease.