Saucony Endorphin Speed 4 vs Nike Zoomfly 6: Which Plated Super Trainer Fits Your Running?

Introduction

The Saucony Endorphin Speed 4 and the Nike Zoomfly 6 are both plated super trainers designed to be fast training shoes, all-rounders, or even stand-ins for race day. Both are genuinely good shoes, and both have earned a place in a serious rotation this year. The Endorphin Speed line has arguably been the best super trainer on the market since the original version launched, and the Speed 4 continues that heritage. The Zoomfly was almost the original plated training partner shoe, but went off the boil in recent versions. With the Zoomfly 6 it is very much back on form.

How They Differ on Paper

The Endorphin Speed 4 costs £180 or $170, while the Zoomfly 6 is £155 in the UK and $170 in the US. On weight, the Speed 4 is the lighter shoe at 255g (9 oz) in a UK 9, compared to 266g (9.4 oz) for the Zoomfly 6. Both have an 8mm drop, but the stack heights differ: the Zoomfly 6 sits at 42mm heel and 34mm forefoot, while the Speed 4 is the lower-stack option at 36mm heel and 28mm forefoot.

Fit is straightforward with both. Sticking to your normal running shoe size is the safe call, with no need to size up or down. Both deliver good heel and midfoot lockdown, and both are comfortable, with the Nike upper standing out as exceptionally comfortable for a super trainer.

Nike Zoomfly 6

The Zoomfly 6 pairs a two-layer woven mesh upper with a dual-density midsole: a top layer of ZoomX foam, the bouncy foamy benchmark of the range, over an SrO2 carrier foam that adds durability and stability. A carbon plate runs through the midsole, slightly more flexible than the one in Nike’s racing shoes but still delivering the stiffness and pop you expect. The waffle outsole offers good forefoot and heel coverage with a centre cutout to save weight.

On the run, the Zoomfly 6 feels cushioned, bouncy, and controlled. It is comfortable even at slow paces, and on longer hard efforts it shines: a 90-minute steady run felt cruisy and protective, with no forefoot discomfort at all. The trade-off is that at really fast paces it can feel slightly big on the foot. It is a fast shoe, but the ride has a touch less ground feel, almost like cruise control even when you are moving quickly.

Saucony Endorphin Speed 4

The Speed 4 uses an engineered mesh upper that is thinner and more breathable at the front, a small internal heel counter, PWRRUN PB foam, and the Speedroll rocker geometry that has been a signature of the Endorphin line. The nylon plate is more flexible than a full carbon race plate, with wings for stability, and the rubber outsole coverage is very similar to the Nike.

On the run it keeps the light, nimble, fast feeling the line has always had. This version is a little cushier at the heel than past models, so heel strikers get a soft ride at easy paces and a nice snap through the rocker as pace rises. The firmer, more direct ride gives you a stronger sense of pace and ground feel. The main caveat is forefoot comfort: when pushing hard over long distances, some forefoot discomfort can appear after about 60 minutes, something the Zoomfly avoids.

Where the Speed 4 earns its keep is at all-out paces. It feels natural to run genuinely fast in, and it can stand in for a full carbon race shoe in hard sessions, performing almost as well. In a punishing session of 24 x 1 minute on, 30 seconds float, followed by a 6K at around marathon pace, it delivered pace-hitting performance you would expect from a carbon shoe.

Which One to Buy

Both shoes are excellent all-rounders, and neither should be discounted. The deciding factors are training style, ride preference, and price, especially in the UK where the Nike is considerably cheaper while the US prices are identical.

If you prioritise long miles, marathon training runs, and long hard tempo sessions, the Zoomfly 6 has the edge thanks to its extra underfoot comfort. It is a great daily trainer that also has a lot of speed. If you want a fast trainer to race in, especially shorter races, or to hit the track for short reps, the Endorphin Speed 4 has more pace in it. It is a very good fast trainer that can also handle daily runs. Ride feel matters too: big cushioning and bounce point to the Nike, while ground feel and a fast rocker turnover point to the Saucony. For a training style built around lots of long runs, the Zoomfly 6 is the easier recommendation, while runners who chase all-out sessions may prefer what the Speed 4 offers.

Conclusion

The Endorphin Speed 4 and Zoomfly 6 are two of the strongest plated super trainers available, each with slightly different strengths. Choose the Nike if you want maximum comfort for long miles and a bouncy, protective ride. Choose the Saucony if you want a faster-feeling, nimbler shoe that can double as a race-day stand-in. Either one would be a welcome addition to a rotation.