 The market for wearable activity trackers has grown prolifically in recent years, with increasing numbers of consumers using them to track, measure, and ideally improve their health and wellbeing. Empirical evidence tends to support wearables as valid, reliable, and effective health behaviour change tools, however little research has been conducted to understand experiential aspects of the devices, particularly thier effects on users’ psychological wellbeing and affect. This study addresses this literature gap by exploring wearable users’ affective responses to their devices and how these relate to personality traits and individual differences.