Adidas Adizero SL2 vs Asics Novablast 4: Two Daily Trainers With Very Different Missions

Introduction

The Adidas Adizero SL2 and the Asics Novablast 4 sit in the same price neighborhood but do very different jobs. The Novablast 4 has become a favorite marathon training daily trainer, while the SL2 is the newer addition to Adidas’s speed-oriented lineup. After extensive testing of both, the comparison turned out to be far closer than it first appeared, and choosing between them really comes down to what you want from your everyday miles.

Two Trainers, Two Philosophies

The Adizero SL2 is Adidas’s speed-oriented daily trainer, built with the Adizero design language: streamlined, stripped down, and fast-looking. It uses Lightstrike Pro foam, the same racing foam found in Adidas’s faster shoes, which gives it a bouncy, energetic character.

The Novablast 4, meanwhile, sits in Asics’s marathon training silo alongside the Superblast, part of the more modern, bouncy, exciting line rather than the traditional Gel shoes. It comes in at $140 and delivers a huge amount of stack, support, and comfort for the money. It may be the most foam you can get at that price.

One thing worth noting: both shoes need some miles to break in. Neither was at its best straight out of the box.

Stability and Cushion: Where the Novablast 4 Wins

The Novablast 4 packs 42mm of foam in the heel, and it feels taller than anything else in its class. The wide base is immediately visible from behind, and when you simulate a heel landing, the shoe plants flat and stays planted. The SL2, with its softer and bouncier Lightstrike Pro core, wobbles noticeably more in comparison. Early runs in the SL2 were genuinely unstable; it was described as the most unstable shoe ever tested, and it took real miles to settle down.

If you need a bit of prescriptive stability and want some fun baked in, the Novablast 4 is the clear pick. The extra padding around the upper and that broad platform make it the more comfort-oriented, protective shoe, well suited to bigger runners and long time on your feet.

Foam Feel: Soft Versus Firm

The SL2 is one of the softest daily trainers tested, right up there with the New Balance 1080 v13. If you do not like soft shoes, the Novablast 4 or the Puma Velocity Nitro 3 are solid alternatives. The remarkable thing about the SL2 is that despite the softness, the Lightstrike Pro foam keeps a density that stops it from bottoming out. It responds well to force and power, and neither shoe bottoms out at least up to 90 minutes of running.

The Novablast 4 has been taken up to a 22 to 23 mile long run and performed great. The SL2 has handled 10 to 12 miles comfortably so far, with a longer test still pending. Neither shoe offers much ground feel, especially the Novablast 4, which has essentially none.

Comfort and On-Foot Feel

On foot, the difference is dramatic. The Novablast 4’s upper has a cotton t-shirt-like material with generous padding, but it is not very breathable and it was not a great summer shoe, with feet heating up noticeably in warm conditions. Stepping into it, you feel about half an inch taller and noticeably more stable through the heel.

The SL2 feels far more streamlined, lighter on the foot despite being only around 20g lighter on paper, and less bulky. For a 30-minute jog, a walk, or casual use plus some gym time, the SL2 is much more natural; the Novablast 4 feels like overkill, a tool for a specific long-mileage job. If comfort is your number one factor, the Novablast 4 wins hands down. If you want just enough of everything and nothing you do not need, that is the SL2.

The SL2 also gets better rubber: more coverage front and back than the Novablast, and a quality compound that is just as sticky and durable as Continental rubber. The Novablast 4 is one of the worst shoes tested in wet weather, so if wet-weather capability matters, the SL2 is the safer bet.

Speed and Versatility: Where the SL2 Pulls Ahead

The Novablast 4’s secret is protection for weight: around 280g in a typical size, lighter than the Saucony Ride 17, Nike Pegasus, or Puma Velocity Nitro 3, while offering more cushion both vertically and in width. It is not a fast shoe, though. In a fast-running test, it was simply not designed for it; it is planted, tamer, and does not encourage turnover.

The SL2, by contrast, has handled fast workouts impressively: a 200 to 800 meter ladder at around five-minute mile pace, and mile repeats at six-flat. On easy miles it also performed well, including a six-mile recovery run. It is the versatility champion, capable of everything from relaxed miles to speed sessions, in the mold of a do-it-all shoe.

Which One Should You Buy?

If you want maximum marathon training comfort and protection at $140, the Novablast 4 delivers. It pampers your legs through long miles and stays stable under fatigue. If you want the most fun and speed in a versatile daily trainer at $130, the SL2 is the pick: fast, bouncy, streamlined, and grippy in the wet.

For summer short-and-fast running, lean SL2. For protected winter mileage and long, comfortable sessions, the Novablast 4 makes more sense. Both are excellent at their intended purpose, and neither is trying to be the other.

Conclusion

These are two of the best daily trainers available right now, with very different spins on everyday miles. Choose the Novablast 4 for tall, stable, protective comfort over long distances. Choose the Adizero SL2 if you want a softer, faster, more versatile shoe that handles speed days and easy runs alike.