DFA α1 + ectopic detection
Detrended Fluctuation Analysis derives the α1 scaling exponent from your heart-rate-strap RR intervals. Values around 0.75 mark the aerobic threshold (AeT/VT1) — a research-validated real-time proxy for your first ventilatory threshold without lab testing. cellTrainer computes α1 live, with Runalyze-compatible artifact filtering (samples with > 5 % artifact rate are dropped to avoid feeding a sparse-strap noise burst into the scaling estimate). The same RR stream feeds an ectopic-beat detector that flags premature beats and compensatory pauses live and classifies them as singles, couplets or runs — using a 7-beat rolling baseline with configurable prematurity / pause thresholds.
SmO2 + O2Hb + HHb
Direct muscle-oxygen measurement via NIRS — supported sensors: Train.Red FYER 1.0 and FYER 2.0. cellTrainer extracts not just SmO2 (%) from the proprietary frame but also Oxyhemoglobin (O2Hb) and Deoxyhemoglobin (HHb) — three metrics instead of one, letting you tell oxygen consumption apart from perfusion changes. Use the live trace to find your aerobic and anaerobic threshold breakpoints, pace intervals so the muscle actually recovers between reps, and verify whether you're really training in the zone your heart-rate target says you are.
Core body temperature + Heat Strain
Live core body temperature and Heat-Strain monitoring via the greenTEG CORE2 thermal sensor. cellTrainer reads CBT (°C), skin temperature, and the derived Heat-Strain Index (0–10) tick-by-tick over BLE — and forwards HR to the trainer or watch in parallel. Use it to gauge true thermal load (not just air temperature), pace heat-acclimation work, or know when today is not the day for VO₂max — based on physiology, not feel.
Auto-control with manual override
When a workout is loaded and a compatible smart trainer or treadmill is paired, cellTrainer drives the target speed/incline (Run) or power (Ride) live so each interval ramps in on its own. Adaptive: nudge the physical levers or the in-app +/- buttons mid-rep and the offset persists through the rest of the step instead of being snapped back to the script. Hands stay free for the work, the device tracks the plan.
Plays well with your platforms
intervals.icu, Garmin Connect, Strava, Dropbox, HiDrive cloud storage, a local folder, Home Assistant for room temperature/humidity — cellTrainer talks to all of them. Pick any combination as workout source (the app pulls scheduled workouts from intervals.icu, Garmin, Dropbox or HiDrive), as auto-export target (FIT, XLSX, CTD — toggle per format and per destination; Strava receives the FIT as a new activity in your feed), or both. No mandatory cloud, no vendor lock-in: configure once and the app fits whatever stack you already have.
Switches & gamepad shortcuts
Pair a BLE switch (Zwift Click, Cycplus BC2) or connect a gamepad (any GameController-compatible model — tested with the 8Bitdo Zero 2) and bind the buttons to start, stop, pace tweak, fan up/down or workout-step skip. No more reaching for the phone mid-session — every assignment is per-sport, so Run and Ride can map the same hardware to different actions.
AI coach summary after each session
Optional 3–5-sentence post-session debrief: did you hit the workout target, what physiological effect was achieved (zone time, intensity factor, DFA α1 progression, HRV anomalies, heat strain), what stood out. Powered by your own OpenRouter key — pick any model (Claude, GPT, Gemini, …), keep cost and privacy in your hands. Report lands in the stop overlay, the .ctd archive, and the .xlsx export.
Your data, your call
No cloud lock-in. cellTrainer itself doesn't host any data — every export is opt-in and configured per user. You decide which session goes where: intervals.icu, Garmin Connect, Strava, HiDrive, Dropbox, a local folder, or nowhere at all. Toggle each destination per format (FIT, XLSX, CTD) so a session can land on one platform and skip the rest. Uploads only fire after you tap Save — stopping a session never sends anything on its own.
