A new meta-analysis of 11 studies shows that mobile device-enabled interventions can help increase people's physical activity. The study, published in the Journal of Medical Internet Research, is the first meta-analysis of its kind, according to the authors.

The 11 studies looked at a broad range of mobile interventions, a few of which seem out of date in the current market. Eight of the 11 used text messaging to offer motivation and report activity. Four used smartphone apps, and two used Personal Digital Assistants, or PDAs.

"You go to conferences and there's a lot of talk about mobile health interventions," said Jason Fanning of the University of Illinois at Champagne-Urbana, one of the authors on the study, "but we didn't have a concrete or objective way of looking at this." Fanning says this foundational data will give a comparison point for future studies, possibly involving newer technologies.

A total of 1,351 individuals participated in the 11 studies. Three studies reported no effect, but the others all showed a positive effect. It was difficult to pull together aggregate data, Fanning said, because the studies used different metrics for success when it came to increasing physical activity: different studies used self-reported activity, pedometer data, accelerometer data, and metabolic equivalents.

Though there wasn't enough data to draw statistically significant conclusions, Fanning said the effectiveness of the studies suggested a few trends. He said interventions that involved goal setting seemed to do better, and that frequent engagement predicted success.

"Those interventions that were interacted with most frequently were more effective, especially with an SMS-based intervention," Fanning said.

Activity trackers and companion apps are already available in the market, of course, such as the Fitbit One, Misfit's Shine, Jawbone's UP bracelet and BodyMedia's FIT armband. Fanning says he's looking forward to efficacy data on those products.

"In the near future there will be a small number of validation papers coming out on some of those devices, and that will be interesting," he said. "If those are more valid, you’ll see a much higher saturation of those devices in a research context."