assistant: You're in the sweet spot for a cushioned daily trainer that can handle both your easy miles and the long-run work ahead. At 85 kg with a heel-strike pattern and a 4:30 goal, you need a shoe with enough stack to absorb impact over 18–20 milers, but not so much that it feels sluggish on tempo or moderate-effort days. The good news: you don't need a racing flat yet — that's a decision for 8–10 weeks before race day. I'd lean toward **Mount to Coast C1 v1** as your primary build-up shoe. It's built for exactly this phase: long-run protection with a 42.0/36.0 mm stack that won't bottom out under your body weight, a moderate rocker that plays well with heel strikers, and high energy return so you're not dragging on those 18-milers. The wide forefoot fit and true-to-size length mean you can dial in lockdown without hot spots on long efforts. At $180, it's a solid investment for 500–600 miles of training. **New Balance FuelCell Rebel v4** is your faster-paced alternative. It's lighter (210g vs 261g) and more responsive, so it shines on tempo days and shorter runs where you want to feel quick. Seth James DeMoor notes the wider, more stable landing platform works well for runners who want a lighter trainer without sacrificing underfoot stability — that matters for your heel-strike pattern. At $139, it's also a budget win if you want rotation variety. The caveat: The Ginger Runner flagged durability concerns for heavier runners on the low stack (34.0/28.0 mm), so this works best as a secondary shoe for faster work, not your sole long-run trainer. **Brooks Adrenaline GTS v25** is the plush recovery option if you want a third shoe for easy days. It's heavier and softer (DNA LOFT v3 with nitrogen infusion), designed for standing/walking comfort as much as running. The 10.0 mm drop is higher than the other two, which some heel strikers prefer, but expert reception is mixed — it's a safety net, not a standout pick. **One clarifying question:** Are you planning to rotate shoes (say, C1 for long runs and easy days, Rebel for tempo/speed work), or do you want a single workhorse shoe for the whole build-up? That'll help me refine whether you need a third option.

assistant: Perfect — you're thinking like a smart marathoner. Build-up shoes are about durability and comfort over 500+ miles, not speed. Here's what I'd reach for: **Mount to Coast C1 v1** is your anchor. It's purpose-built for long-run work: 42.0/36.0 mm stack absorbs impact at your body weight without feeling pillowy, a moderate rocker that plays nicely with heel strikers, and genuinely high energy return so you're not dead-legging on mile 16. The wide forefoot and true-to-size fit mean lockdown stays solid even when your feet swell on long efforts. This is your 18-miler shoe, your 14-miler shoe, your "I'm doing serious distance" shoe. **Saucony Endorphin Azura v1** is your daily workhorse and tempo option. At $150, it's a steal — excellent expert reception, high cushioning (no maximal bloat), and neutral platform that won't fight your heel strike. It'll handle your 6–8 mile easy runs and give you enough responsiveness for moderate-pace work without the weight of a pure recovery shoe. Think of it as the shoe you'll log the most miles in. **Nike Vomero Plus** is your recovery-day insurance. At 281g with 43.0/33.0 mm stack and ZoomX foam, it's plush enough to let your legs recover after hard efforts, but it's not so soft that it'll mess with your running economy on easy days. The 10.0 mm drop matches your heel-strike preference. Use this on the day after long runs or tempo sessions. **One follow-up:** How many shoes are you comfortable rotating? If you want to stick with two, I'd drop the Vomero and alternate C1 (long/moderate) and Azura (easy/tempo). If you want three for maximum durability and recovery, all three gives you a solid toolkit.