Wearable devices and associated systems that provide real-time feedback aim to encourage healthy behaviours. However, while the research base has grown considerably, results continue to paint a mixed picture when demonstrating wearables’ ability to increase levels of physical activity. Given these recent developments, this commentary explores the key reasons why wearable devices and other mobile technologies often fail to change behaviour. We also provide several suggestions that could feed into future research designs and maximise the success of subsequent interventions. These recommendations aim to stimulate interdisciplinary discussions by encouraging clinicians and researchers to consider how these technological advances can be effectively leveraged, and become a core component of preventative medicine in the 21st century.