Kardiacs

Kardiacs is your training partner for riding, running, walking and hiking — indoors on a smart trainer or treadmill, outdoors on roads and trails. No sign-up wall: open it and start — and your recorded GPS never leaves your phone.

Every workout is personalized: power, pace and heart-rate targets from your own Critical Power (CP/W′) for rides and critical speed for runs, fitted from your history, Health Connect, or a quick profile.

RIDE TOGETHER, OFF THE GRID
• Form a group in person with a QR code — no signal, no account, no server in the middle
• Everyone on one map, numbers on their card; a run or walk group is paced for its slowest
• Talk to the whole group hands-free or push-to-talk, end-to-end encrypted
• Group chat with camera photos; what you say is typed into it by your own phone and read aloud to riders who missed it
• The leader's route reaches every phone; any rider can ask for a stop — a café, water — or call for help

NOTES WITHOUT STOPPING
• Riding alone? Unmute and talk, and what you say becomes a note on your phone; a photo is a note too
• Every session's notes and chats are kept under Settings → Chat & Notes, to read, export or delete

YOUR CALENDAR
• Every ride, run and walk on its day, with your fitness curve under it
• Schedule workouts, once or repeating, with a reminder before each; planned sessions badge the icon
• Import your history from FIT files or a Strava or Garmin archive
• Each session's notes and chat are summarised, on your phone only, into a line on that day

OUTDOOR SESSIONS
• Explore: drop a pin, pick a workout, and get loops that fit it
• Commute: A-to-B routes from stops and saved routes
• Long-press a café to make it a stop; restrooms and drinking water near your route are one tap away
• Turn-by-turn cues spoken aloud, and a satellite view that switches itself on over unpaved ground
• Routing runs on your device: with a map downloaded, plan, reroute and navigate with no signal
• Anywhere on Earth: search a place and download its map — as many as you like

INDOOR TRAINING
• Automatic trainer control (ERG) on compatible Bluetooth trainers — or switch it off and ride the intervals yourself
• Just Ride: resistance up and down, in your hands
• Treadmill sessions with grade-adjusted pace targets
• A workout library at your thresholds, or build your own, on the phone or at app.kardiacs.com

WEATHER BEFORE YOU GO
• Hourly conditions, UV and air quality for where you are

PROGRESS
• Every session ends on its analysis over the route: every chart labelled and scrubbable
• Your fitness over time: Critical Power, W′, critical pace and VO₂max — and a daily readiness read from Health Connect
• Every ride is written down as it happens, so a flat battery can't lose it
• Share any session as a FIT file, with or without the track; your history follows your account

YOUR GEAR, ORGANIZED
• Bluetooth trainers, treadmills, heart-rate monitors and sensors
• Send a route or workout to your bike computer, and import the rides it records
• Wear OS companion app coming soon: your numbers on the wrist, and start, pause and stop from there
• Saves completed workouts to Health Connect

WHERE YOU RIDE STAYS YOURS
• Position is stripped from every activity before it syncs anywhere
• Speech is recognised on your phone; no audio is sent anywhere
• Delete your account and everything under it, from Profile

Kardiacs is free, supported by ads; there is nothing to buy.

Notes: Kardiacs speaks 23 languages. Android 13 or later, on phones and tablets. Weather by Open-Meteo. Gemini Nano writes readiness notes and session summaries on phones that have it. ERG requires a compatible Bluetooth (FTMS or Wahoo) smart trainer. Group voice needs Wi-Fi Aware between Android phones and a phone whose security module can sign; any phone still shares positions, chat and cards over Bluetooth. Dictation needs on-device speech recognition. You must be 16 or older to use Kardiacs, and 18 for accounts and structured workouts.