Asics S4+ Yogiri Introduction

If you didn’t read my review of the S4, the 4 S’s stand for speed, stability, safety and sub-4. The S4 is a friendly racer designed for runners looking to achieve a sub-4 hour marathon time. It’s more stable, more durable and cheaper than most flagship marathon racers.

This concept is a great one because most long-distance racing shoes available for the public to buy are the same exact models that elite athletes use. Elite athletes have superior running form so it doesn’t make sense for casual runners to use the exact same racing shoes as world-class athletes.

The S4, which was released in 2023 was exclusive to Japan. The S4+ Yogiri is now available in the USA, at both Running Warehouse and the ASICS website. The price of $200, however, is much higher than in Japan (around $50 more).

When I reviewed the S4, I said that it was an excellent choice for a runner looking to achieve sub-4 in the marathon. I would have chosen the S4 when I attempted to run my first sub-4. It was a much better choice than the ASICS Magic Speed because it had more cushioning and used a better midsole foam. It was also more stable, more durable and cheaper than the Metaspeed Sky and Edge.

Yogiri means “Night Fog” in Japanese and they named it this because of the launch colourway which evokes imagery of speed, silence and stealth. The S4+ Yogiri weighs 235 g (8.3 oz) for a men’s US 9, which is 5 grams (0.2 oz) lighter than its predecessor. It has stack heights of 40 mm/34 mm.

Asics S4+ Yogiri First Impressions

My first run was a moderately-paced 12 kilometre run. I expected it to be noticeably softer but the ride felt very similar to the previous version. It was one of the firmest riding shoes I’ve tested in a long time. There also wasn’t much energy return from the new FF Turbo+ midsole foam.

The positives were that the new upper was supremely comfortable and the sole was very stable thanks to the firm ride. The carbon plate was still very stiff, which was one of the things that I liked about version 1.

It didn’t feel as propulsive or energetic as a super shoe but it felt comfortable going at 5:40 per km (9:07 per mile) pace which is what it was designed for. I was a bit disappointed that it didn’t feel like a big improvement over its predecessor.

Asics S4+ Yogiri Upper

The S4+ Yogiri’s upper has a roomy interior (suitable for wide feet) unlike the snug, racing fit of the Metaspeed Sky and Edge Paris. It’s true to size and you don’t need to go a half size up like the previous version.

The engineered mesh is softer and more comfortable than the plastic-like upper of the S4 but breathability isn’t as good. The flat tongue is not gusseted but I didn’t experience much tongue slide during runs.

There’s ample padding in the soft collar and heel tab so comfort is high and foot lockdown is very good. There’s no reflectivity but the laces are notched, racing laces that feel very premium.

Asics S4+ Yogiri Sole Unit

The S4+ Yogiri is marketed as a road racing super shoe but the bad news is that it doesn’t feel like one; it feels more like a speed trainer. The main reason for this is that it’s midsole feels firm and flat without any bounce or squishiness.

It feels like they’ve tuned the FF Turbo+ foam in the S4+ to be denser and firmer: it doesn’t feel the same as in the Sky Paris/Edge Paris or the Superblast 2. The bottom layer of foam in the midsole is Flytefoam, an even firmer foam than FF Turbo+. This makes the midsole really stable, which is the S4+’s main selling point.

It’s designed to be stable enough and offer enough support for at least 4 hours of racing. I did a 40 km training run which lasted longer than 4 hours and it offered enough support for the duration of the long run. I wished it had more energy return because the flat ride made the run feel boring.

For me, the S4+ only feels comfortable for my steady pace (around 5:40 per km). It’s too firm for my easy runs and it’s not propulsive or lively enough for uptempo runs so I don’t view it as a very versatile shoe. If you’re using it for racing, it’s only suitable for marathon pace.

The full-length carbon plate in the S4+ is wider than in the Metaspeeds to increase stability. It has some flexibility to make the ride feel more natural at slower speeds.

The outsole is the best feature of the S4+. It consists of an abundance of thick, ASICSGRIP rubber that provides excellent traction on wet and dry surfaces. It’s also highly durable as there isn’t much wear showing on my pair after 120 kilometres. You can get plenty of training and racing out of this outsole.

Asics S4+ Yogiri Conclusions

If you’ve run in the ASICS Metaspeed Sky/Edge or any other super shoe, you won’t be happy with how the S4+ Yogiri rides because it’s noticeably firmer and less engaging. In order to increase the stability, ASICS has made the midsole too firm.

They should have used FF Blast+ Eco as the bottom midsole layer (like the Superblast 2) instead of Flytefoam which is an old, dull midsole foam from the stone ages. The Superblast 2 feels a lot more exciting and engaging- it also costs $200.

I didn’t enjoy testing the S4+ Yogiri and it won’t stay in my rotation. I prefer the ride of the ASICS Magic Speed 4 which has a thicker midsole with more cushioning and is just as stable as the S4+. The Magic Speed 4 is $30 cheaper than the S4+ but it has a heel stack height above 40 mm, making it illegal in World Athletics races.

The speed trainers from other brands such as the Hoka Mach X 2, PUMA Deviate Nitro 3, Saucony Endorphin Trainer and New Balance SC Trainer V3 are all more lively and cheaper than the S4+ Yogiri. They are also good sub-4 marathon racing options.