The reference marathon shoe against the strongest claim to its crown.
The ASICS Metaspeed Sky Tokyo is 35g lighter (183g against 218g), the ASICS Metaspeed Sky Tokyo is £35 cheaper at RRP (£250 against £285), and both hold their foam for roughly 250km of racing. Both are inside the World Athletics 40mm road limit.
Weight · men's US 9
Price · UK RRP
Competitive life · km before the foam fades
■ marks the better figure, where better is not a matter of taste
Alphafly 340mm — on the limit
Metaspeed Sky Tokyo39.5mm — on the limit
| Specification | Alphafly 3 | Metaspeed Sky Tokyo |
|---|---|---|
| RRP | £285 | £250 (advantage) |
| Weight | 218g | 183g (advantage) |
| Stack | 40 / 32mm | 39.5 / 34.5mm |
| Drop | 8mm | 5mm |
| Road legal | yes | yes |
| Plate | carbon fibre | carbon fibre |
| Foam | ZoomX with Air Zoom pods | FF Leap over FF Turbo+ |
| Competitive life | ~250km | ~250km |
| Price per km of life | £1.14 | £1.00 (advantage) |
| Fit | standard | standard |
| Underfoot | balanced | balanced |
| Built for | Half · Marathon | 10K · Half · Marathon |
| Economy gain | 3.4–4.6% | 3.5–4.7% |
= 5:20/km
Modelled economy gain adjusted for pace and your current shoes; ranges reflect the spread published between individual runners. Full method.
| Race | For the time | For the money |
|---|---|---|
| 10Kat a reference 45:00 | Only the Metaspeed Sky Tokyo is built for this distance. | |
| Half marathonat a reference 1:45:00 | Metaspeed Sky Tokyo−1m 33s to −2m 13s | Metaspeed Sky Tokyocheaper per second saved |
| Marathonat a reference 3:45:00 | Metaspeed Sky Tokyo−3m 6s to −4m 26s | Metaspeed Sky Tokyocheaper per second saved |
Reference times, trainer baseline, whole-life economics. Your own time changes the answer — use the reading above.
Still the reference marathon shoe. The Air pods give a propulsive forefoot that nothing else quite replicates, and the wider platform makes it manageable late in a race when your form has gone.
■ Caution Sits at exactly 40mm — legal, but with no margin. It is a lot of shoe for anyone racing slower than about 4:30/km, and the forefoot pods reward a genuine forefoot strike.
For stride-length runners — the Sky is built to let your stride open up rather than turn over faster. Arguably the best all-round marathon shoe currently made.
■ Caution ASICS splits the line by running style. If you race by increasing cadence rather than stride length, the Edge is the correct shoe and this one will feel wrong.
Manufacturer-stated specs unless marked estimated on the shoe sheet · last reviewed 2026-08-13 · prices are UK RRP.