By Brian Metzler

If you’ve read shoe reviews I’ve written in recent years, you know that the various iterations of the Saucony Endorphin Speed have been my favorite training shoes since the release of the first one in 2021. I’ve run in just about every shoe released in the past few years, but the Endorphin Speed has consistently been the best. Why? In short, the sum of the parts has been greater than the whole, and it’s had the best combination of everything I seek out in an everyday  training shoe without being too little or too much. It has had the right amount of high-rebound midsole foam, but it’s not maximally cushioned. It’s light and zippy, but it’s not super light and flimsy. It’s smooth and responsive, but not exceptionally bouncy or sharp like some carbon-plated racing shoes. Plus, especially with the third edition, it’s been uniquely versatile – a shoe that can truly do everything very well.

Each new Endorphin Speed model has been slightly different from the previous one. That’s the nature of the shoe game – brands are under pressure to continually tweak and update each model, no matter how popular or high-performing they might be. I loved the Endorphin Speed 2, but I found the update that became the third version wasn’t quite as good, as Saucony seemed to force it into being more of an all-around trainer for a wider range of runners. The upper was a bit sloppy, and the vibe was somehow not quite as energetic as the previous versions. The challenge for shoe manufacturers is that the changes are typically already in the works before the current one is fully vetted by consumers. In other words, as I am serving up a review about the new Endorphin Speed 4 here, Saucony has already begun the revisions that will appear in next year’s Endorphin Speed 5. That said, Saucony has done a great job at keeping the best materials, the best features and the essence of the shoe intact to keep a similar vibe going through the first four editions, so I’m quite pleased with my first 10 or so runs in  the Endorphin Speed 4.

What’s New: The Saucony Endorphin Speed 4 retains  the juicy PWRRUN PB midsole that everyone has loved, as well as the semi-rigid/semi-flexible, wing-shaped nylon propulsion plate, the curvy rocker shape of Saucony’s Speedroll geometry, and the rear-foot structure from the interior heel counter. However, it also features a softer sockliner, an updated outsole, a revised, dual-layer mesh upper and a brilliant new aesthetic design that seems to evoke a feeling of speed and efficiency. (The looks of a shoe have nothing to do with how it performs, but the looks of a shoe can definitely create an emotional stirring within a runner to want to run faster or better while wearing it.) On the materials alone, this shoe gets at A for its updates. Plus, it’s the same price ($170) as last year’s edition. 

Fit/Feel/Ride: The Saucony Endorphin Speed 4 fits true to size with a medium-volume interior and a moderately roomy toe box that gives ample space for my toes to flex and splay. It feels more spacious than the Endorphin Speed 2 but about the same as the Endorphin Speed 3. The step-in feel is comfortable but not opulent, although the new sockliner offers a slightly softer feeling underfoot and contributes to the softer overall sensation of feel and ride of the shoe. The fit is enhanced by the new upper, which has several different zones of airy but sturdy mesh, an updated lacing system (with ghillie loops instead of eyelets) and a partially gusseted tongue that feels like a snug-fitting bootie construction once it’s laced up. The new edition is slightly heavier than the previous version (about a half ounce, which is barely noticeable except that it is) and it feels like it’s “more shoe,” even though the stack heights are the same.

The ride of the Speed 4 is what’s most important, and it’s certainly been enhanced by the improved fit. In general, it’s smooth, lively and compliant for any pace. It feels softer and more cushy than the previous iterations and, like the third version, not nearly as agile and snappy as the sports car vibe of the second edition. It’s still a very responsive shoe that feels great running at a variety of speeds, even if it’s never going to be the nimble speedster that it was in its second edition. If you view this model as a better version of an everyday trainer (which it is) and not solely a speed-day shoe (which it isn’t), then it’s a win-win situation. 

Why It’s Great: It’s great because it’s better than the previous version, which, by the way, was still a very good shoe. The PWRRUN PB midsole is still one of the best midsole materials in the business, and Saucony put better complementary upper and outsole materials into this version of the shoe. After my initial runs, it was clear that the fourth edition is a combination of the best aspects of the second and third versions. It’s a fairly light, comfortable, smooth-riding shoe with a lot of energetic pop, but with more stability than the second version and a better fit than the third version. If you had never run in any of the first three versions of the Endorphin Speed, you will try on this shoe and might be convinced it’s going to be the best training shoe you’ve ever worn.

Specs

Weights: 7.5 oz. (women’s 8); 8.2 oz. (men’s 9) Heel-Toe Offset: 8mm (36mm at the heel/28mm at the forefoot)

Why You’ll Love It: It’s a versatile everyday trainer that does everything you ask of it extremely well. If you’re interested in an energetic ride for most of your running, this is one to consider. I love the soft, responsive sensation for the training runs I have done in it – long runs, recovery runs, tempo runs, etc. – and believe it could suffice for faster workouts and races for some runners. No, it’s not an all-out racer, nor is it an electric speed workout shoe. But if you’re a new runner, a novice runner or a committed mid-packer who is looking for a comfortable shoe with a lively, bounce-back feeling all the way through a 5K, 10K, half marathon or marathon, the Endorphin Speed 4 has got you covered.

Pro: The new outsole has less rubber coverage in the heel but more in the forefoot with a grippier grid pattern that offers better traction on wet surfaces. Improved traction is gained from both the structure and the material of the carbon-rubber lattice-style segment that covers the entire forefoot.

Con: In evolving the Endorphin Speed into a do-everything, everyday trainer, it’s lost a bit of its all-out speed vibes that it had in the second edition. It’s slightly heavier and not as poppy. That’s not a horrible thing, but I’d be less apt to take the Endorphin Speed 4 to the track for 400- or 800-meter intervals, and would instead choose another lighter, faster and more agile trainer. But I could be splitting hairs because most runners might find this ideal for intervals.