Stress and Autonomic Balance Lab

How the model works: sympathetic and parasympathetic activity are each scored from 0 to 100 percent. They depend on the time of day, sleep, the daily stressor, how long the stress has lasted (which builds allostatic load), sleep debt and recovery activities. Heart rate and HRV (RMSSD) follow the balance; the ECG beats are generated from that heart rate with breathing linked variation. Cortisol follows a daily rhythm with a peak after waking at 7 am, a rise after the stressor, and a flatter shape with long lasting stress and short sleep. Simplified for learning.

Predict items: choose first, then watch the organ respond. Number items: the worked solution builds step by step after a correct answer or when you ask for it, and units that cancel are struck out in red.