Abstract: Techniques are disclosed for generating user information from autonomic nervous system (ANS) parameters and continuous ANS monitoring. Some embodiments may provide a wearable device, comprising: a photoplethysmography (PPG) sensor; a motion sensor; and processing circuitry configured to: determine one or more monitoring conditions; determine whether the one or more monitoring conditions are satisfied based on monitoring motion data from the motion sensor; capture the blood flow data with the PPG sensor when the one or more monitoring conditions are satisfied; determine time-interval data indicating times between pulses based on the blood flow data; determine an ANS condition based on the time-interval data. The blood flow data and/or time-interval data may be captured and aggregated from multiple discontinuous periods of time when monitoring conditions are satisfied.