FF Leap vs ZoomX

This is the comparison everyone frames as a brand rivalry but is really a chemistry one: ASICS's FF Leap is an aliphatic TPU (A-TPU); Nike's ZoomX is PEBA. A-TPU is the foam most often named when people ask whether PEBA has finally been dethroned. Both anchor flagship racers and plateless supertrainers — here's where they actually behave differently, paired shoe by shoe.

The 30-second answer

Different polymers, not just different brands. ZoomX is Pebax — lightest and springiest when fresh. FF Leap is aliphatic TPU — a hair firmer and, by the consistent reviewer read, more resistant to fatigue: it holds its bounce deeper into a shoe's life and through cold weather. Reviewers describe FF Leap shoes (the Superblast in particular) as more stable at training paces, where full-ZoomX shoes can feel sloppy. One wrinkle: ASICS often pairs FF Leap (A-TPU) with FF Turbo Plus (PEBA) in the same racer, so the Metaspeed shoes are dual-chemistry, not pure A-TPU.

What you're actually comparing

They are not the same chemistry. ZoomX is a foamed Pebax (polyether block amide) — see the PEBA page. FF Leap is aliphatic thermoplastic polyurethane — see the A-TPU page. Its A-TPU identity is confirmed across teardown reviewers (RunRepeat, Doctors of Running), and ASICS markets FF Leap as its lightest, softest, and bounciest foam yet. Where ASICS stacks both foams, you get a PEBA layer and an A-TPU layer in one midsole.

ASICS's racing approach is also unusual. Where Nike ships one marathon racer (Vaporfly) that aims to suit any stride, ASICS ships two — Metaspeed Sky for runners whose stride lengthens at race pace, Metaspeed Edge for runners whose cadence increases — both built on the FF Leap / FF Turbo Plus pairing, with geometry and plate placement tuned differently. The Metaspeed Ray (2025/26) goes nearly full FF Leap in a supercritical grade for the lightest possible weight, parallel to the Adidas Adios Pro Evo concept.

Where they actually differ on the run

The clearest split is durability of feel. A-TPU's headline trait, repeated by reviewers, is that it resists fatigue: Believe in the Run noted the Superblast 3's A-TPU "doesn't lose that bounce after 100 miles," and RunRepeat frames A-TPU as holding its energy return both within a race and across a season better than PEBA. PEBA is lighter and arguably springier when brand new, but reviewers widely report PEBA midsoles packing out measurably after 200–300 miles.

Stability at slower paces is the other recurring split. Full-ZoomX shoes are often described as sloppy or unstable at conversational pace — Believe in the Run and Kofuzi have made this point about the Vomero Plus and Vaporfly across versions. FF Leap shoes hold a line better at training paces; in the Superblast that's helped further by the firmer EVA/OBC carrier under the A-TPU. Same use case, different feel.

At the racing end, the Metaspeed Sky Tokyo and Vaporfly 4 are closer than the chemistry suggests, because the Sky's PEBA top layer sits closest to the foot. Doctors of Running reads the Sky as marginally firmer and more directive, the Vaporfly as more cushion-first. The Metaspeed Edge Tokyo is the genuinely different shoe — lower stack, more forefoot rocker, FF Leap over FF Turbo Plus — with no direct ZoomX equivalent; the nearest Nike shoe is the Zoom Fly 6, which is a daily-trainer-as-racer (trainer-grade ZoomX over EVA), not a true racer.

Head-to-head, shoe by shoe

Which should you pick

Stride pattern, stability preference, and how long you want the bounce to last matter more than the brand. The rough decision matrix:

The Superblast vs Vomero Plus question doesn't have a wrong answer — both are widely-recommended plateless supertrainers. The deciding factor is usually stability and durability of feel (lean Superblast / A-TPU) vs maximum cushioned bounce (lean Vomero Plus / ZoomX).

Every shoe in our catalog using each

Sources

• ASICS — Metaspeed series launch (ASICS's commercial framing of FF Leap as its lightest, softest and bounciest foam (the A-TPU identification is from the lab teardowns below)).
• RunRepeat — Metaspeed Sky Tokyo cut-in-half ("FF Leap is not a PEBA foam like FF Turbo+, as it's made from A-TPU"; FF Turbo Plus = PEBA).
• Nike — ZoomX technology page (Nike's commercial description of ZoomX; teardowns identify the racing grade as Pebax and the trainer grade, e.g. Vomero, as TPE-based).
• Hoogkamer et al. — A Comparison of the Energetic Cost of Running in Marathon Racing Shoes, Sports Medicine, 2018 (peer-reviewed; energetics of the super-foam-plus-plate construction).
• RunRepeat — The ultimate guide to running shoe foams (independent lab measurements across foam types, including A-TPU vs PEBA energy return and fatigue).

See also

• A-TPU — the aliphatic-TPU chemistry behind FF Leap.
• PEBA — the chemistry behind ZoomX.
• Supercritical foams — the processing used in the Metaspeed Ray.
• ZoomX vs. Lightstrike Pro — PEBA vs. TPEE, Nike vs. Adidas.
• ZoomX vs. PWRRUN PB — Nike vs. Saucony, both PEBA.
• Back to the Foam Atlas