Alpha Amylase

Salivary alpha-amylase (sAA) is a digestive enzyme secreted by the parotid glands in response to beta-adrenergic stimulation of the sympathetic nervous system, making its activity a validated non-invasive surrogate for sympathoadrenal (norepinephrine) activity and acute psychophysiological stress. Unlike cortisol which reflects HPA axis activity with a 15–20-minute lag, sAA responds within minutes to exercise or psychological stress and rapidly returns to baseline, making it ideal for tracking acute ANS arousal and recovery dynamics. Nater and Rohleder (2009) and Papacosta and Nassis (2011) comprehensively validated sAA as a reliable real-time sympathetic nervous system biomarker in athletic monitoring.