The Adios Pro 4 is what adidas races marathons in. Two layers of Lightstrike Pro sit under carbon-infused ENERGYRODS 2.0, and the whole thing comes in around 200 g at UK 8.5 — a 39 mm heel that still feels like almost nothing on your foot.
It suits race day from 10K to the marathon, and the handful of sharpening sessions where you want to rehearse that feeling before you need it.
It is not a training shoe. The foam is soft and packs out fast, the rods turn unforgiving once your form falls apart late in a race, and a shoe this specialised has no business carrying your easy miles. Buy it for the days that count and keep it in the box otherwise.