Original Summary

I lift 3-4x a week and run, and I could never find an app that coaches both seriously. Lifting apps treat running as a footnote. Running apps treat lifting as accessory filler. And nearly every lifting app treats the Apple Watch as an afterthought — a rep counter instead of a coach. (Video above is the Watch app running a full session — phone stays in the locker.) So six months ago I started building Mainstay for myself: an AI strength coach for iPhone + Apple Watch. Periodized programming that plans lifting and running in one week (including the annoying part — how Tuesday's intervals should change Thursday's squats), adjusts based on how recovered you are, and runs the whole session from your wrist. I'm a full-time CEO, so this is nights-and-weekends work. I'm on build 78 now, testing it on my own training every day — it's finally at the point where I'd let strangers touch it. This weekend I'm opening ~25 beta slots. Four things the process taught me: Dogfooding finds what QA never will. No test plan would have caught that my rest timer felt fine on paper but infuriating mid-superset, or that the AI's "optimal" exercise order falls apart when you're gassed in week 8 of a block. I rewrote the session engine twice because of things I only felt while sweating. The hardest problem wasn't the AI — it was the interference problem. Getting one plan to respect both a heavy squat day and an interval day in the same week, without one quietly sabotaging the other, took more iterations than everything else combined. Ship embarrassingly narrow. The first version anyone could have touched did one thing: generate next week's lifting. Everything else — the coach chat, the Watch app, the running side — came later. Narrow meant I actually finished things. Building for yourself is a superpower and a trap. Superpower: you always know what "good" feels like. Trap: you're the easiest user to please and the least representative one. That's exactly why I'm opening it up now — I need people who aren't me to tell me where it breaks. If you lift and run and want to kick the tires: mainstay.fit — apply and I'll send the TestFlight link directly. ~25 spots for this first stranger cohort, free during beta; founding testers lock in $149.99/yr founding pricing when we launch. And for the builders here: what's the thing dogfooding caught for you that testing never would have?   submitted by   /u/alcsooners [link]   [comments]

  • 情报分类：硬件与数码
  • 分类依据：内容涉及硬件、数码产品或通信卡
  • 信息来源：Reddit · SideProject
  • 发布时间：2026/9/21 03:12:53