The habit construct, and proxy measures of habit such as frequency and recency measures of past behaviour (Bagozzi & Warshaw, 1990), has been a topic of considerable interest to health psychology theorists and researchers interested in the factors related to health behaviour (Ajzen, 2002; Chatzisarantis, Hagger, & Smith, 2007; Hagger, Anderson, Kyriakaki, & Darkings, 2007; Hagger, Chatzisarantis, & Biddle, 2001; Hagger, Chatzisarantis, & Harris, 2006; Norman & Conner, 2006; Norman, Conner, & Bell, 2000; Ouellette & Wood, 1998; Verplanken & Faes, 1999). Gardner (2014) recently reviewed the literature on the effects of the habit construct in health-related research. In the review, habit was defined as a ‘as a process by which a stimulus automatically generates an impulse towards action, based on learned stimulus-response associations’ (p. 4). Gardner's review represents a step forward in understanding the various definitions of habit in the social psychological literature applied to health, and provides considerable insight into the definitions of habit, types of habitual behaviour, effectiveness of previous models and tests of habit in the health-related literature, the limitations of habit research, avenues for future research and implications for interventions.