The Helix watch app puts the daily loop on your wrist: this morning’s recovery, today’s strain against its ceiling, and last night’s sleep, all glanceable without reaching for the phone. The watch app ships with the free tier Free; you need the watch, not a subscription.
Live workout tracking
Start a workout from the watch and it records heart rate continuously, shows which heart-rate zone you are in, and displays your strain climbing in real time during the session. That last part changes how you train: instead of finding out tonight that you overshot your strain ceiling, you can watch yourself approach it and decide, mid-session, whether today is the day to cross it.
Guided tests on the wrist
The fitness test drivers run from the watch, which is where they belong: the Cooper test (a GPS-measured 12-minute run), guided 4x4 intervals, and threshold detection all need live pacing cues and heart rate on your body, not a phone in your hand. The tests themselves are part of the VO₂max Lab, which is a Pro feature; the watch is just where you run them.
Data flows both ways
The watch and phone split the work. The watch is the sensor: it records heart rate, workouts and sleep. The phone is the brain: it reads that data from Apple Health, computes recovery, strain and everything else, and syncs the results back so your wrist always shows the current scores. You do not manage this; it happens in the background, and identical data is never sent twice.
For the exact breakdown of what needs the watch and what still works with just an iPhone, see with & without a watch. The short version: overnight HRV, live strain and staged sleep all want the watch on your body; the phone alone gets you estimated sleep and honest “no data” labels rather than invented numbers.
Battery, honestly
Helix wants the watch on your wrist overnight, because that is when the recovery inputs are recorded. A watch charging on the nightstand is a watch that gives you no score tomorrow. That makes charging strategy a real part of using Helix, so here is what actually works:
- Charge during your morning routine. Shower, coffee, breakfast is comfortably enough to carry most watches through the day and the night after.
- Or top up before bed. A charge while you wind down in the evening means you sleep with a full battery and never think about it during the day.
Either routine works; the failure mode is having no routine and discovering a dead watch at 11pm.
To keep scores on the watch face itself, see complications & widgets.