When asked about my PhD evaluating the NHS Choices Smartphone app, Couch to 5K, many people wrongly assume that I am focusing on reducing obesity. Although the behaviours are often linked, they are separate, and I am studying how to promote engagement in low levels of physical activity (PA). This is because if there is any health epidemic, it is not in obesity, but inactivity.
Given that inactivity is more prevalent – and more toxic - than obesity – as confirmed by the recent report from the European Prospective Investigation into Cancer and Nutrition (EPIC) study, we need new and effective approaches to promote activity in more people. The EPIC study, which tracked 334,161 male and female Europeans over 12 years, is especially important because it signals a turning point; funders have long seen obesity as a higher Public Health priority.
The EPIC study also highlights that inactive individuals only require a brisk walk of 20 minutes each day to secure substantial health benefits. This is less than current government guidelines for PA. It must be stressed here that this recommendation is only for those doing very little activity; there is danger of misconstruing this message as meaning that this is the only level of benefit. Indeed, because of its dose-response relationship with many health conditions, for most people, more than 20 minutes of daily PA will continue bringing even more benefit. That said, achieving the recommendation makes a substantial difference to reducing the risk of developing lifestyle-related health conditions.
Yet, even doing 20 minutes of brisk walking each day is not as easy as it might seem, especially for the least active individuals. This behaviour needs to become habitual to bring the real benefits. To help support the development of such a habit, typically requires some sort of intervention that supplements the will-power that others take-for-granted.
Currently, face-to-face interventions are extremely costly and not especially effective. Worse, these approaches only reach a select few individuals (often the so-called 'worried well') rather than those with most to gain from changed behaviour. Technology can alleviate these issues; mobile phone-based interventions are cheap to deliver and they reach large, worldwide populations. Indeed, around 50% of Smartphone owners use fitness applications ('apps'); many of these – such as 'Couch to 5K' - are free and available in many languages. They represent a tidal wave of potential for improved health behaviour.
The authors of the EPIC study acknowledge that 20 minutes of PA per day is a bare minimum recommendation. The persuasive techniques employed within the better fitness apps can help inactive people to not only meet this low threshold but also exceed it. In that way, they will accumulate the further benefits of additional PA. The best apps have in-built links to social media sites to harness social support, allow users to track their personal progress, set goals, and compare achievements against peers. These are all important behaviour change techniques that, once more people deploy them in relation to their PA, will allow us to downgrade the idea of inactivity as a big killer.