Tell it how much time you've got — it finds the loop
Set a max distance, a max time, or both, and Kardiacs builds a handful of loop options that start right where you are. Each one comes with the climb and the effort laid out, plus a heads-up if a section is steeper than your current fitness can hold pace on — so you spend less time planning and more time out there.
Get there fast. Arrive presentable.
Your route gets planned around your own fitness level, so it gets you to work or class quickly without leaving you drenched and out of breath. Kardiacs keeps the effort as low as it can, whatever the distance — a ten-minute walk or a ten-mile ride — and calls every turn on the way.
Turned around? Just tap back.
Wander further than planned and Kardiacs routes you straight back — to your car, your front door, or wherever you started. Need to be home by a certain time? Say so mid-ride and it plans a way back that fits, with the distance, climb and effort up front. Maps for your area download ahead of time, so losing signal deep in a trail never turns into losing your way.
Know what you're heading out into
Hour-by-hour forecast, wind speed and direction, air quality, UV index and how much daylight you've got left — plus any active weather alerts for where you are. It's right on the home screen, so checking the sky is part of getting ready instead of another app to open.
Built around you — or built by you
Indoors or out, every structured session is shaped around your own fitness — intervals, targets, intensity factor and training load all scaled to you, with heart rate and power keeping each block exactly where it should be. Want to take the wheel yourself? Build a workout from scratch, down to the interval, the target, and the zone.
Your whole setup, paired once
Save your trainer, power meter, heart-rate strap and watch together as a kit, and they reconnect the moment you start a ride. Kardiacs drives the trainer's resistance to hit each interval's target watts, so the workout holds its shape without you touching a thing.
A mix built for the session, not a shuffle
Kardiacs builds each ride or run its own mix from your own listening, matching every track's tempo to the cadence the interval is asking for — calm warm-ups, driving efforts, easy cool-downs. Skip, favorite, or stop the mix any time, from your phone or your wrist.
It reads your recovery, not just your effort
Sleep stages, heart-rate variability and stress get tracked right alongside your training and factored into what comes next. Running low? It steers you toward an easier route, or suggests a full rest day, instead of piling on another hard effort.
Every workout, broken down
Pace and power curves, heart-rate drift, time in each zone, training load, fitness and fatigue trends — every past ride and run gets the full breakdown, in interactive charts built to dig into. See exactly how a session landed, and how your fitness is actually trending.
Start it, run it, steer it — from the watch
Pick the activity, start the session, and watch your zones, heart rate, cadence and distance without ever reaching for your phone. The route map comes along too, and so do the music controls — the phone can stay in your pocket the whole way.
Your location and health data stay on your phone
Activities sync without GPS coordinates, and your planned routes and saved addresses never leave the device. Readiness runs entirely on-device, so nothing health-related is uploaded — and you can point playlist generation at Apple Intelligence on your own iPhone instead of the cloud, or turn AI features off altogether.