Can the Web make people more fit?

It's a question hot on the minds of everyone from health insurers to gym owners to public health officials. 

In a new study published in the journal Preventive Medicine Reports, researchers have found a way to make the Web -- and social media -- more effective for improving people's exercise habits.

In a randomized controlled trial, the researchers created a website where 217 graduate students enrolled in free exercise classes at the University of Pennsylvania gym. Part of the group also received promotional messages from the University, including highly engaging motivational videos and infographics emphasizing fitness tips and the importance of exercise.

Meanwhile, another part of the group saw no advertising messages. Instead, members of this group were placed into social networks with six of their peers. While these peer groups remained anonymous to one another, participants were regularly updated on each other's fitness achievements. They could monitor each other's progress on the website, and when one signed up for a weightlifting or yoga class, for example, the others were notified by email. As a control group for the two interventions, a final group of participants received no further follow-up through the study.

By the end of the 13 week study, the findings were clear. Promotional messages caused an initial bump in class attendance, but the motivational effects quickly wore off. The promotional messages had almost no long term effect on class participation.

Program-assigned "buddies," on the other hand, were much more effective at motivating people to exercise. As the weeks went by, the motivating effects increased, producing a substantial growth in enrollment levels among people in peer networks.

What this new study reveals is that these same positive behavior signals are also powerful in our online networks, and can be harnessed for the social good. This approach could be applied not only to encourage exercise, but also to promote vaccinations, medication compliance, and preventative care.