Pairing contextual texts and activity tracking leads to people moving more, according to a small study of 48 outpatients of an academic CVD prevention center in Baltimore, Maryland that was published in the Journal of the American Heart Association.

The study, which was conducted in three phases, looked into whether activity tracking and texting interventions among smartphone users aged 18 to 69 years would improve their physical activity. 

During the first week of the the trial, researchers established a baseline for physical activity for the participants. In weeks two and three, the researchers split the participants into two groups. One group, with 32 people, were unblinded, while the other 16 were blinded. All participants received an activity tracker, the Fitbug Orb, but only unblinded participants got to see their activity data. 

Then, for the last two weeks of the study, participants in the unblinded segment were randomly split up into two groups. One group received automated, personalized texts that offered users positive reinforcement. The texts were sent when participants were on track to reach or had already reached their daily goal as well as to motivate them when they were not on track to reach their goal. These messages were sent three times a day and were scheduled to be sent when the user was eating breakfast, at lunch, and after work. All participants were asked to walk 10,000 steps per day.

At the baseline, 48 percent of participants had a daily step count over 10,000 steps. Some 56 percent from the blinded group and 44 percent from the unblinded group. In the first phase of the study, the blinded group decreased their activity by 6 percent, or a mean of 616 steps. Meanwhile, the unblinded group increased their activity by 4 percent, or a mean of 408 steps.

In the second phase of the study, the blinded group saw an 11 percent decrease in activity, the unblinded group that didn’t receive tests saw a decrease of less than 1 percent — a mean of 200 steps — and the unblinded group that received texts increased activity by 25 percent, or 2,334 more steps per day.

“The mActive trial lends support to the notion of new mHealth devices as facilitators, not drivers, of behavior change, because sequential randomization suggested that unblinding to device data did not significantly modify behavior, whereas coupling it with smart texts did,” researchers wrote in the study. “If sustained, the change in physical activity from the mActive tracking-texting intervention may be clinically significant.”

Because of the trial's limited size, researchers said the study could be categorized as a pilot trial and the data should be interpreted as exploratory evidence that can be used for a more definitive future trial.