Kardiacs: Trainer & Route Nav

Free ride, run & walk coach: ERG-controlled smart trainer, offline turn-by-turn maps, AI playlists, Apple Watch support — and GPS trace that never leaves your phone.

Kardiacs is your personal training partner for riding, running and walking — indoors on your smart trainer or treadmill, outdoors on roads and trails. There's no sign-up wall: open it and start — and your recorded GPS trace never leaves your phone.

Every workout is personalized. Kardiacs models your fitness with Critical Power (CP/W′) and adapts power targets, pace targets, and heart-rate zones to you — built from your workout history, Apple Health, or a quick profile setup.

OUTDOOR SESSIONS • Explore: drop a pin, pick a workout, and discover loops that fit it, with turn-by-turn guidance • Commute: plan A-to-B routes from stops and saved routes, and get where you're going • Long-press a café, park or bike shop on the map to make it a stop — your route re-plans through it, or starts there if you have none yet • Restrooms and drinking water near your route, with one-tap stops through the nearest • Loops and commutes reshape as you ride, so a detour still ends at the distance you chose • Pick your sport on a live map that flies to where you are and stays with you • A map that turns the way you're travelling, over terrain drawn in relief, with the weather layered on top • Turn-by-turn cues on the phone and the wrist, including "Turn around" when you must reverse • Routing runs on your device: download the map for where you're going and plan, reroute and navigate with no signal at all • Pick a route and the map fetches the ground along it before you leave Wi-Fi • Walking with pacing that respects your age and fitness

MUSIC THAT MATCHES YOUR EFFORT • Control Apple Music without leaving your session • AI Workout Mixes: a playlist beat-matched to your cadence or stride, curated on device by Apple Intelligence • Queue playlists, favorite songs, and see what's up next

INDOOR TRAINING • Automatic trainer control (ERG): your workout drives the resistance on compatible Bluetooth smart trainers • Treadmill sessions with grade-adjusted pace targets • Targets that ramp between intervals instead of jumping, on the phone and on your wrist • Live dashboard with power, pace, and heart-rate zone bars — your target bracketed so you always know where to sit • A structured workout library, resolved to your personal thresholds • Create your own sessions with the custom workout builder

WEATHER BEFORE YOU GO • Hourly and daily conditions, UV, sun times, air quality and severe-weather alerts • On a planned route, the wind resolved against the road still ahead of you

PROGRESS • Track your fitness over time: Critical Power, W′, and VO₂max • Post-session summaries with charts of every metric • Long-press any zone card mid-session for a live history graph

YOUR GEAR, ORGANIZED • Connects to Bluetooth trainers, treadmills, heart-rate monitors and sensors • The Garage groups your bikes, shoes, and devices into kits for indoor and outdoor • Apple Watch companion app for wrist-based control and heart rate • Live Activity on the Lock Screen and Dynamic Island • Saves workouts to Apple Health

WHERE YOU RIDE STAYS YOURS • Recorded GPS never leaves your phone — position is stripped from every activity before it syncs anywhere • Health data is read on device and never uploaded • Only the routes you choose to save sync, and only to your own account — never to a shared pool • Map telemetry is switched off before the map ever starts

Kardiacs is free to use, supported by ads. This app can be free since I'm a solo developer and Kardiacs is a side project of mine. Please contact the support email if there are any issues.

Notes: Weather by Apple Weather. Apple Music features require the Apple Music app (and an Apple Music subscription for full playback). AI Workout Mixes require Apple Intelligence. Automatic resistance control requires a compatible Bluetooth (FTMS or Wahoo) smart trainer. Turn-by-turn guidance requires location access. You must be 16 or older to use Kardiacs; accounts and structured workouts require you to be 18 or older.