Saucony Endorphin Speed 4 Review: A Suitable Successor?

The original mutant was the shoe that set the internet ablaze with joy and positive reviews. Versatile and fun, Saucony had a winner. How does the fourth version compare?

Saucony Endorphin Speed 4 – Big Shoes to Fill

The Saucony Endorphin Speed series is a very special animal in the running shoe market. This model released in 2019 with the now-famous Mutant colorway. It immediately became a favorite for many runners and for  different types of runs ranging from slower jogs up to marathon paces and beyond. Many of us experienced a  new sensation with that PEBA-based midsole (something fairly new back then), a nylon plate and the distinct snappy ride. During the COVID lockdown, I really remember the internet going crazy about this shoe. Saucony had a winner. Is the Endorphin Speed 4 as great as its predecessor?


Weight in Saucony’s sample size: 233g/8.20z


Official Stack: 36mm/28mm (8mm drop)


Upper – Great Comfort and Almost There.

The upper of the Saucony Endorphin Speed 4 could have been a state-of-the-art upper. The new material is extremely soft, well padded and offers an exquisite step-in feel.  The tongue is one of my favourites among the recent shoes I’ve tested. Just the perfect thickness and again the material used improves it even further. It is gusseted and said gusset is bigger in surface (it starts earlier and runs longer towards the forefoot). Great midfoot wrapping in combination with the new lacing system that offers to added-on eyelets (see in orange on the pictures).


Overall the upper is a remarkable upgrade compared to v3, and that’s primarily due to the new mesh. Much softer and nice against the feet. The fit is still on the narrow side of things but I’m happy to report that I didn’t experience any little-toe rubbing in this shoe (unlike the previous versions). It runs true to size and a tad shorter compared to the recently released Ride 17 or the Endorphin Pro 4 (which runs quite long). So what’s the issue with it? Well the heel could do with a bit more padding. Also, perhaps a narrower cup. It’s quite large and my average sized heel has too much room, resulting in a bit of heel movement. That being said, I can live with it and I would still rate this upper very high.

Endorphin Speed 4-08
Endorphin Speed 4-18

Saucony Endorphin Speed 4 Midsole – More of the Same

PEBA-based PWRRUN PB all the way from heel to toe. A nylon plate. 36mm in the heel. 28mm in the forefoot. 8mm drop.


So wait, does that mean nothing changed?


The new Saucony Endorphin Speed 4 has received some upgrades around the midsole but they’re rather minor. The external sculptings a la Novablast are one of them. They look good and the launch colorway helps with that, in my opinion. My bending test (just trying to bend the shoe and see how much forefoot flex it has, which is very subjective of course) showed a bit more flex in the forefoot. However,  that results from a change in the outsole, I believe (see below). Other than that, it’s in the heel that I’ve seen some changes, with a softer landing feel in the heel area compared to the previous version.

The Ride

The Saucony Endorphin Speed 4 still has that distinct thing that made the series so popular. A lot of soft cushion and dynamic responsiveness with a best-in-class forefoot snapiness. Moreover, the additional flex in the forefoot makes it feel more natural but also requires a bit more power to maintain paces. I, personally, enjoy the denser forefoot feel but nevertheless consider it still a very plush shoe and something I’d see working better for cadence runners and lighter people. Finally,  the extra width in the midsole makes the ride more gentle and less wild, but the shoe isn’t stable by any means with the soft PEBA midsole.

Endorphin Speed 4 Outsole – Getting Grippier

Saucony’s rubber outsoles have been a nightmare for me in the past (like on the Endorphin Elite), and while this one is a bit grippier and offers a touch more traction thanks to the redesigned pattern, it still falls short of my expectations. But let’s welcome the step in the right direction, especially when shoes like the Ride 17 are not getting the update. In terms of noticeable changes, the outsole doesn’t connect the forefoot and heel anymore thus creating more decoupling and allowing for more flex (see above).

Endorphin Speed 4 - Studio-4
Endorphin Speed 4-12

Conclusion – Does the Endorphin Speed 4 Carry the Lineage?

Saucony did not miss the mark with this update to the Endorphin Speed series. Whilst the Speed 4 doesn’t get a ton of changes but what has been done goes in the right direction. Firstly, the upper is definitely the biggest improvement and that level of comfort is really something to applaud. Next, the midsole and ride will still please cadence runners the most but people like myself (midfoot, stride runner, 70kg) should prefer this version to the previous ones (a denser forefoot feel, more surface to push on, slightly wider midfoot). All in all the shoe will deliver and if you see the Speed 3 on sale, you can still get it as it isn’t years behind the new version.

Alex Filitti Meta Circle


29 years old

183cm (6′) – 68kg (148lbs)

Mid/Forefoot striker – Stride runner

Moderate pronator


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