Motivation is a key component of behaviour change. With the focus on the motivational aspects of behaviour change in mind, Self-Determination Theory (SDT) has become an increasingly commonly used theory to design health behaviour change interventions . According to SDT individuals adopt or change behaviour on the basis of internal satisfaction and fulfilment, termed as intrinsic motivation. Alternatively, individuals are less likely to adopt or change behaviour when a reward or inducement provided by an external person is used to compel a person to act, known as extrinsic motivation. Environments that support intrinsic motivation optimise behavioural effort, persistence and performance. In contrast, environments that coerce through rewards serve to diminish behavioural effort, persistence and performance .