ARC works great with just your iPhone — and gets richer with whatever you've already got. Daily Pulse score, adaptive plans, calendar-aware fueling, voice coaching, race pacing, and proactive notes from your last few activities. Most of it free, forever. No new device to buy.
Every layer adds depth. Nothing past the iPhone is required.
Most wellness platforms now sell you the device + the subscription. ARC's bet is different: the device is the one in your pocket.
| Feature | ARC | Whoop / Oura / Fitbit |
|---|---|---|
| New device required | No | Yes (~$200–$400) |
| Works with the watch you already own | Yes (any HK-compatible) | No (their device only) |
| Adapts to your existing training plan | Yes (import or coach-built) | Their plans only |
| Most features free, forever | Yes | Subscription required |
| Continuous biometrics (HR, sleep, HRV) | Needs a wearable (your call) | Their hardware |
Honest read: if you want a 24/7 biometric wristband, theirs is the better hardware. If you want a coach that works with what you have, that's ARC.
One anchor card with the 2–3 things that matter for you today: today's session with "why" reasoning, the meal moment, run-day pre/post-fuel, micro-challenge, evening check-in, wind-down. It looks 3 days ahead too — "long run Saturday, bank sleep + carbs tonight."
One number, 0–100, that tells you what your body's asking for today. Built from your training load, recovery (sleep, resting HR), and consistency. Lives on Today and your home-screen widget. Locks once per day so app + widget always agree, with a trend arrow vs your trailing week. Tap to see why it changed.
Tell ARC what's in your kitchen (real ingredients only — no spices). Suggestions reorder around your matches. Vegetarian, vegan, pescatarian — the picker shows only what fits your diet. Tap into a meal you like; ARC bubbles it up next time.
Weekly volume, long-run progression, run heatmap, race predictor with honest range bands (no fake precision). Every chart comes with ARC's one-line take — numbers + verdict, not stats alone.
ARC notices things — new monthly best at a distance, training load shifting, comeback after a break, 100/200/300 active days. Each shows up in the notification bell with "what to try" guidance. Suppression rules keep it useful, not noisy.
Connect your calendar — Apple, Google, any account on your iPhone — and ARC reads your free/busy times (times only, never event details, all on-device). It suggests the workout window that actually fits your day, and the night before, flags when tomorrow's plan collides with a packed schedule.
Set ARC's depth — Light, Balanced, or Full. Light keeps it to one quiet anchor and only the entries that matter; Full surfaces everything ARC notices, with deeper reasoning. The coaching meets you where you are.
Every run, every PR, every plan adaptation, every "what ARC noticed." After 90 days, ARC knows your patterns better than any app you'd switch to could rebuild. Year in Motion grows; the coach logbook shows the why behind every change.
Plan import runs on-device. HealthKit data stays local. No public feed, no leaderboards, no selling your data. Your activity is yours.
Whether you've never run, you're coming back, or you're chasing a race — pick a persona during onboarding and ARC sets up your plan, days, and coaching tone in one tap. Switch any time.
Real early users, anonymized. Each uses a different mix of gear — ARC adapts to all three.
"I don't own a watch and I walk more than I run. ARC gave me a goal of moving 5 of 7 days, the widget shows where I am for the week, and the bell tells me when I hit a milestone. Nothing pushes me to buy anything I don't need."
"My Garmin records my runs. ARC tells me what to do before and after — fueling, hydration, when to bias easy. I imported my marathon plan as a photo. ARC reads it, layers coaching, and my Garmin runs the workout."
"The peri persona changed everything. ARC weights recovery and strength more than just mileage. Vegetarian-aware meal plans. And when my training load got too high, ARC told me in plain English to bias easy."
ARC reads everything through Apple Health. Whether you log via a fitness watch (Apple Watch, Garmin, COROS), a recovery device (Oura, Whoop, Fitbit), or an activity app (MapMyRun, Nike Run Club, Adidas Running) — as long as it writes to Apple Health (most do, by default), ARC sees your runs and walks. Apple Watch users get structured workouts pushed straight into the stock Workouts app with intervals, target paces, and haptics. iPhone-only? Just use Apple's Fitness app — ARC reads your steps and walks and starts you on a walk-to-run plan, no extra gear. Your gear handles the recording. ARC handles the coaching.
ARC doesn't record your runs — your watch (or your phone) handles that. We don't shame missed days, post your runs publicly, or compete with your music app. We don't run leaderboards or ask you to log every meal. We don't sell your data, ever — plan import runs on-device; HealthKit data stays local. The tracker's job stays the tracker's; ARC layers coaching on top — before, during, and after.
Most of ARC is free. Premium unlocks the deeper coaching.
A short window into what we're building next.