Is the secret to increased physical fitness in your back pocket? Using a smartphone app, participants in an eight-week trial were found to walk over 1,000 steps - or half a mile - extra per day. The research was carried out by the National University of Ireland Galway and is published today in the British Journal of General Practice. This is thought to be the first randomised controlled trial research evidence showing that use of a smartphone pedometer app, which provides feedback on physical activity and goal achievement, is associated with a clinically meaningful increase in physical activity. Not only did participants see improvements in step count, but some of those who used the smartphone app also had decreases in blood pressure and weight. A growing body of evidence shows that behaviour-change programmes using computer tailoring can be effective in changing lifestyle risk factors, such as physical activity. The emerging field of captology — the study of computers as persuasive technology — has described many of the mechanisms by which mobile phones have become such an important platform for changing human behaviour. Dr Liam Glynn, a Senior Lecturer in General Practice at the National University of Ireland Galway, and a practicing GP, led the research project called SMART MOVE: “Captology is a very interesting area for medical practitioners. The penetration of smartphones into our everyday lives, along with the availability of so many apps promoting physical activity, represents a unique opportunity in population health. There is real potential within healthcare to use these devices to explore, understand, and positively change human behaviour. “Our research has shown that significant improvements in physical activity rates can be achieved, which we know can lead to long term health benefits such as reduced risk of cardiovascular disease and diabetes”. “Rather than just providing more evidence that tracking in any form supports behaviour change, the results of this trial represent an important step forward in the challenging issue of physical activity promotion by describing an intervention that is effective, accessible and potentially sustainable. Further data with longer follow-up are being collected from the current trial of the pedometer app conducted across six European countries,” added Dr Glynn. The trial recruited 90 participants, which were randomly divided into two equal groups. A control group who did not use the app and an intervention group who did. The app was based around the concept of a pedometer with a live and accurate recording of step count as the participant went about their daily activity. This provided constant feedback and tracking of physical activity with a visually appealing graphic display of step count history and the ability to goal set and receive visual rewards for goals achieved. Both groups in the trial were given similar physical activity goals and information on the benefits of exercise. However, and crucially, only the intervention group was told how to use the app to help them achieve these goals. The results from the trial were striking in that use of a smartphone application increased physical activity over an eight week period, compared to the control. The magnitude of change (over 1000 steps/day or approximately a half mile), is clinically meaningful and, if continued is expected to result in long term health benefit. While the control group demonstrated an initial increase in physical activity, this was followed by a decrease to baseline activity by the end of the trial period while the increase in activity seen in the intervention group was maintained. The potential advantage of using a smartphone application is that no additional piece of technology such as pedometer is required and people generally carry their mobile phone devices on their persons continuously. It has been suggested that significant improvements in public health in the future are more likely to come from behavioural change rather than from technological or scientific innovation. The results of this smartphone app trial would suggest that novel technologies such as mobile devices and related smartphone applications may become an important driver for the behavioural change process.