Saucony Endorphin Speed 3 Long Run Review: A Big Step Forward in the Speed Line

Introduction

The Endorphin Speed line has long been one of the most popular tempo shoes among runners, and the third version arrives with meaningful changes where they count. After a 10-mile, 16.1 km run mixing easy miles, 1 km reps at 10K pace, and a 2.5-mile fartlek finish, the Speed 3 comes across as a clear improvement: better wet-road grip, a softer and more energetic midsole, and the same light, carefree feel that made the earlier versions fun.

Testing the Endorphin Speed 3 on a 10-Mile Mixed-Pace Run

The run covered a quiet, flat 1 km loop on the edge of town, with average pace landing at 7:37 per mile (about 4:44 per kilometer) in 17°C conditions, some showers, and 19 mph winds from the south southwest. That mix of easy running, reps, and fartlek speed play makes a good stress test for a shoe that sits between a daily trainer and a race shoe.

One important note: this pair was slightly modified before the run. The stock insoles in the Speed 3 are really thin and do not add much step-in feel. Swapping in a pair of crushed ZoomX insoles (the type first used in the Tempo Next%) is a simple upgrade that brings a slightly more Endorphin Pro 3 feel. If you have a spare pair lying around, it is a worthwhile tweak.

Upper: Comfortable, Plush, but Check the Laces

The upper feels a little more plush than the Endorphin Speed 2, and using a runner’s knot gives a much better lockdown. There is enough tongue padding that no pressure points develop on top of the foot.

There is one catch: the stock laces are quite elastic and stretchy. Midway through the long run, lockdown noticeably loosened, which broke the connection between the foot, the footbed, and the midsole you want from the nylon plate. A quick retightening solved it, but swapping in less stretchy laces is a sensible move. That good foot-to-midsole connection is what lets the plate deliver its little extra push.

Midsole: Soft, Bouncy, and Consistent

Across paces from 8:15 per mile up to 10K effort, the midsole felt fantastic. It was especially good on the fartlek section, picking up speed toward a target in the distance and firing back just as readily. The foam this year is a little bit softer, with more squash, feeling airier than the denser feel some found in the Speed 1 and 2.

The ride feels compressive, forgiving in terms of perceived effort and recovery, and consistent between the left and right shoe, which is not always a given. The weight-to-performance ratio feels spot on: light enough for daily use, but ready for tempo, threshold, or faster running without complaint. It is easy to see why the Speed series is so well regarded. It simply makes running enjoyable.

Outsole and Wet Grip: The Biggest Fix Over Earlier Versions

Wet roads were the weak point of the Speed 1 and 2, and this was the main reason for testing the Speed 3 in the rain. Good news: the new rubber pattern and positioning on the XT-900 carbon rubber outsole is a genuine improvement. On tight bends and curves in the wet, there was never a moment of feeling about to slip or topple over.

With the earlier versions, it was easy to unconsciously hold back when approaching corners out of fear of sliding. With the Speed 3, the outsole just feels like it is gripping the floor. That, plus the improved foam, makes it a big step forward in the line.

Things to Consider Before Buying

A little tongue slipping and the stretchy laces are the main niggles, both manageable with a lace swap or a runner’s knot. The bright blue colorway will not suit everyone, either. If you want everything the Speed 3 offers with a slightly reduced upper, the Pro 3 exists at a higher tier, but for most tempo and daily running, the Speed 3 hits a sweet spot.

Buying Advice

The Endorphin Speed 3 works as an enjoyable daily shoe that can still handle faster sessions without compromise. It suits runners who found the Speed 1 and 2 too rigid or dense, and anyone who runs in changeable weather will appreciate the wet-road grip. If you are coming from an earlier version, this is the upgrade you were waiting for.

Conclusion

The Saucony Endorphin Speed 3 is a big improvement on an already well-loved shoe. More assured in wet conditions, a squishier and more energetic midsole, and the same light, fun-loving ride. Fix the laces, maybe upgrade the insole, and you have one of the most enjoyable tempo trainers around.