Need help with Viking 4x4? Email support@viking4x4.app and you'll hear back from a human — usually within one business day.
Before you write in
- No heart rate showing? Make sure your Apple Watch is nearby and unlocked — the Viking 4x4 Watch app launches automatically when you press start — and that Viking 4x4 has Health permissions (Settings → Privacy & Security → Health).
- Zones look wrong? Check your max heart rate setting — the default estimate can be off for individuals. Here's how to find your real max heart rate.
- Workout didn't save? Confirm Apple Health write permission is enabled. Workouts save to Health with your chosen activity type, heart rate samples, and calories.
General protocol questions are covered in the FAQ and the complete protocol guide.