assistant: Got it — you're a high-mileage runner (60–70 km/week is solid), midfoot striker, and the Zoom Fly 6 isn't working for you fit-wise. Before I narrow the picks, one quick question: **what's the fit issue with the Zoom Fly 6?** Is it too tight in the forefoot, loose in the heel, or something else? That'll help me steer you toward a shoe that actually works for your foot shape rather than just swapping for another model. Once I know that, I can recommend a tempo/marathon trainer that'll be a genuine upgrade for your training cycle.

assistant: Got it — you want a **true** tempo/speed shoe, not an all-rounder pretending to be one. The Zoom Fly 6 is versatile by design (it's marketed as a daily/tempo hybrid), which means it's compromising on the snappy, responsive feel you're probably looking for at tempo pace. For your profile — 60–70 km/week, midfoot striker, marathon training focus — I'd lean toward **Saucony Endorphin Speed v5** as your top pick. It's a dedicated speed trainer with a nylon plate (snappier than the Zoom Fly's carbon, lighter feel), high cushioning that still lets you feel the road, and reviewers consistently praise it as more energizing and nimble than heavier plated shoes. At $175, it's close to the Zoom Fly's price but actually commits to the tempo role. If you want to stay with Nike but get a true speed shoe, the **Adidas Adizero Takumi Sen v11** is worth considering — it's lighter (184g vs the Zoom Fly's 244g), sits in true racing territory, and Doctors of Running calls it "a massive upgrade" with a much softer, bouncier ride than the previous version. That said, it's more of a 5K/10K racer than a marathon-tempo trainer, so it depends on whether you're doing shorter speed work or longer tempo runs. A third option: **ASICS Megablast v1** if you want max cushioning with tempo versatility. It's got the same drop as the Zoom Fly (8.0 mm), but the FF BLAST MAX midsole is bouncier, and it's explicitly built for marathon-pace work — though the narrow forefoot might be a concern given your Zoom Fly fit issues. **Quick clarification:** when you say the Zoom Fly hasn't been fitting well, is it the forefoot width, heel lockdown, or overall volume? That'll help me rule out the Megablast (which runs narrow) or confirm the Speed v5 is the right call.

assistant: The Takumi Sen v11 is a sharp pick for pure speed work — it's genuinely a 5K/10K racer, not a marathon-tempo trainer. If that's your lane (shorter, faster intervals and tempo efforts), it's excellent. But I want to be honest: **for marathon training at 60–70 km/week, the Takumi might be overkill and too light for the volume you're putting in.** Here's the trade-off: Kofuzi calls it "aggressive" and "best used for hard workouts rather than days with easy miles mixed in." At 184g with minimal stack (32/25mm) and a fiberglass plate, it's built to shine on the track or in a 5K/10K race — not to absorb the pounding of repeated marathon-pace sessions week after week. **For true tempo/speed work within your marathon cycle, I'd actually stick with the Endorphin Speed v5.** It's the sweet spot: nylon-plated (snappier than the Zoom Fly, less aggressive than the Takumi), high cushioning (37/29mm stack), and reviewers specifically call it out for tempo sessions and marathon-pace work. EDDBUD notes it's "softer and more energizing" than the Zoom Fly; The Run Testers praise its "lively bounce" for fast training without the top-end punch that burns through foam in 100 miles. The Takumi is the racer you'd lace up for a 5K or 10K goal race. The Speed v5 is the trainer you'd use for the 8–10 weeks of tempo and speed work leading into your marathon. **Does that distinction land for you — or are you actually training for a faster marathon goal (sub-3, BQ attempt) where a true racing shoe makes sense?**