The two default answers to “which marathon shoe?” — the reference racer against the best value at the top of the market.
The adidas Adizero Adios Pro 4 is 8g lighter (210g against 218g), the adidas Adizero Adios Pro 4 is £55 cheaper at RRP (£230 against £285), and the adidas Adizero Adios Pro 4 stays fast for roughly 10km longer (~260km against ~250km). 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
Adizero Adios Pro 439mm — road legal
| Specification | Alphafly 3 | Adizero Adios Pro 4 |
|---|---|---|
| RRP | £285 | £230 (advantage) |
| Weight | 218g | 210g (advantage) |
| Stack | 40 / 32mm | 39 / 33mm |
| Drop | 8mm | 6mm |
| Road legal | yes | yes |
| Plate | carbon fibre | carbon fibre |
| Foam | ZoomX with Air Zoom pods | Lightstrike Pro |
| Competitive life | ~250km | ~260km (advantage) |
| Price per km of life | £1.14 | £0.88 (advantage) |
| Fit | standard | standard |
| Underfoot | balanced | balanced |
| Built for | Half · Marathon | 10K · Half · Marathon |
| Economy gain | 3.4–4.6% | 3.2–4.3% |
= 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 Adizero Adios Pro 4 is built for this distance. | |
| Half marathonat a reference 1:45:00 | Alphafly 3−1m 30s to −2m 10s | Adizero Adios Pro 4cheaper per second saved |
| Marathonat a reference 3:45:00 | Alphafly 3−2m 59s to −4m 20s | Adizero Adios Pro 4cheaper 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.
The best value at the very top of the market. Within touching distance of the Evo 2 for performance at half the price and twice the life.
■ Caution The EnergyRods give a distinctive rolling feel that some runners never get on with. Try before you commit if you can.
Manufacturer-stated specs unless marked estimated on the shoe sheet · last reviewed 2026-08-13 · prices are UK RRP.