⏲️Setting exercise duration

For timed work (and Coach Mode), Kairos decides how long an exercise runs using a simple priority order — most specific wins:

• 1. A duration you set on a specific set in the plan builder.
• 2. The exercise's default duration.
• 3. Your per-training-mode preference (set in Coach Mode → Settings — e.g. “Standard = 60s, Cardio = 3:00”).
• 4. The block type's built-in default (Warm-up 30s, Standard 60s, Cardio 3:00, etc.).

Rest times follow the same idea: per-set → exercise default → block default → type default. Set it once globally, or fine-tune per set.