The present invention relates to an assessing system, an assessing method and a computer program for assessing a heart rate of a subject. It finds application in categorizing a physiological response as a condition, in particular in the diagnosis of pathological tachycardia and bradycardia. The assessing system comprises a photoplethysmography (PPG) signal providing unit (10); a motion signal providing unit (20); a parameter providing unit (30) for providing a subject specific parameter; a heart rate determination unit (40); a resting period determination unit (50); an abnormality determination unit (80) for determining an abnormality of the heart rate during the resting period; and an assessing unit (90) for assessing the determined abnormality based on the subject specific parameter. The invention provides a system and a method, which allow for a more reliable assessment of a heart rate of a subject based on a PPG signal of the subject.