Saucony Endorphin Pro 4 vs the Competition: Four Racing Shoes Compared

Introduction

The Saucony Endorphin Pro 4 is a low-weight super shoe tuned for the marathon distance, and it sits in one of the most competitive categories in running right now. To understand where it stands, it makes sense to compare it against the shoes most runners are also weighing up: the characterful Nike Alphafly 3, the excellent Asics Metaspeed Sky Paris, and the Endorphin Speed 4, its nylon-plated sibling.

This comparison focuses on fit, weight, stack height, ride feel and the distances each shoe suits best.

Fit, Weight and Stack: The Numbers That Matter

The Alphafly 3 is easily the widest shoe in this comparison, with roughly 9.7 cm of heel width making it the widest at the back of the shoe. That said, super shoes are generally wide in the forefoot these days, and the Endorphin Pro 4 sits only about half a centimetre narrower in that area.

Weight is close between the two flagship racers: in a UK size 11 / US size 12, both the Endorphin Pro 4 and the Alphafly 3 come in around 247 g. The Metaspeed Sky Paris is the clear featherweight, roughly 40 g lighter than either of those for the same size. The Endorphin Speed 4 goes the other way, adding another 30 g on top of the Pro 4, making it the heaviest of the four.

Heel stack is another interesting point. Measured in hand, the Alphafly 3 appears to have more heel stack than its official spec suggests, possibly due to how the beveled heel area is measured on the sample size and how that scales up in larger sizes. The takeaway for buyers: real-world measurements can differ from the stated numbers, so trust feel on foot over spec sheets.

Saucony Endorphin Pro 4: The Balanced Marathon Contender

The Endorphin Pro 4 shares a stretchy, sock-like knit upper and tongue design with the Alphafly 3, but offers slightly less width in the forefoot and heel. The plate feel is more of a standard carbon ride, with responsiveness spread across the whole foot. That comes largely from a PEBA top layer sitting above the foam, which elevates it over its predecessor.

At marathon pace, roughly around 7:15 per mile for one heavier runner tested here, both the Pro 4 and Alphafly 3 feel superb. The Pro 4 has a slightly more aggressive outsole, which nudges it ahead in grip and ride sharpness. Durability so far is strong, with very little visible wear, and it works across both half and full marathon distances. The stock laces are a bit stretchy, so swapping them for stiffer, shorter laces noticeably improved the fit.

Neither the Pro 4 nor the Alphafly 3 is a great pick for 5K or 10K racing, where the volume of midsole feels like overkill for runners wanting snappier responsiveness. As a marathon weapon, though, the Pro 4 is a banger that remains versatile and hard-wearing.

Nike Alphafly 3: Pure Marathon Magic

Where the Pro 4 feels like a refined traditional carbon racer, the Alphafly 3 is far more present on foot. The unique knit upper and stretchy tongue give it a very distinctive feel, and after a break-in period it just keeps getting better. For longer runs and the later stages of a marathon, it delivers an almost effortless ride.

If forced to choose a single pair for both training and racing, the Alphafly 3 edges ahead for pure marathon use, though traditionalists may well prefer the more conventional feel of the Saucony. It is the more expensive of the two, but the experience at marathon effort is hard to argue with.

Asics Metaspeed Sky Paris: The Lightweight Racer

The Metaspeed Sky Paris is significantly lighter than everything else here, and that lightness translates directly into speed. It is a half marathon and 10K PB shoe that feels amazing the moment it goes on foot, encouraging you up onto the forefoot and relying less on a big stack of foam.

The narrower fit reinforces that racing character. It feels like a race car compared to the more planted Saucony, and it works especially well for lighter runners or anyone more tuned to half marathon distances and below. In a full marathon, that aggressive character can push you too fast too early. The Pro 4, with a touch more heel width and a more forgiving, cushioned feel over the miles, is the better marathon option, and it also looks more durable so far, as the peba-based foam in the Asics needs a bit more care.

There is a small win for the Asics inside the upper: slightly more internal room for voluminous toes, and the stock perforated laces work perfectly without modification. It is also extremely breathable, with one of the best upper designs in this class.

Saucony Endorphin Speed 4: More Trainer Than Racer Now

The gap between the Speed 4 and the Pro 4 has widened this generation. In earlier iterations the two were nearly interchangeable apart from the plate, and some runners even preferred the more malleable nylon-plated Speed for long efforts. This time, the Speed 4 is much heavier, partly due to added stability elements, with less stack than the Pro 4 and more heel width.

That stability element is hard to ignore on foot: a rigid plastic piece can be felt underfoot just behind the ball of the foot, and it does not feel great. Swapping the laces and insole may help, but the overall impression is that this is now a trainer rather than a true super shoe, even though it still carries a super shoe price. Given the weight and cost, most runners would be better served by the Pro 4, which is breathable, durable enough for premium sessions and long runs, and still race-ready.

Buying Advice

• Marathon racing, one pair for everything: the Alphafly 3 has the edge for pure marathon magic, with the Endorphin Pro 4 right behind it and the more traditional ride.
• Half marathon and 10K PBs: the Metaspeed Sky Paris is the standout, thanks to its very low weight and forward-leaning geometry.
• Balanced marathon option with better durability: the Endorphin Pro 4 offers a wider heel, more forgiving cushioning and strong outsole grip.
• Training partner for a Pro 4 racer: the Speed 4 can work, but its added weight, stability elements and high price make the Pro 4 the safer investment.

Conclusion

The Endorphin Pro 4 holds its own in elite company. It is the more durable, slightly more forgiving marathon option compared to the Alphafly 3, and the more marathon-suitable choice over the Metaspeed Sky Paris. The Speed 4 has drifted away from its sibling toward trainer territory, making the Pro 4 the clear pick of the Saucony pair. Choose based on distance: full marathon for the Saucony or Nike, shorter fast races for the Asics.