Changing Behaviors: Personalized Prompts from an App Increase Your Physical Activity

by Adrienne Mueller, PhD
December 19, 2023

Physical activity has many health benefits, including a reduction in chronic diseases associated with aging and leading an inactive lifestyle such as obesity, diabetes, and heart disease. One measure of physical activity is how many steps you take per day – a measure that is easily collected by smart phones, smart watches, or other digital devices. Recently, the MyHeart Counts Cardiovascular Health study collected step count physical activity data from over 50000 users and showed that digital interventions (e.g. app-based prompts to be more active) can increase physical activity. However, this study could not determine what type of digital interventions were the most effective, or whether personalized prompts were more effective that general prompts.

A team of investigators led by Ali Javed, PhD, Daniel Seung Kim, MD, PhD, and Euan Ashley, MD, PhD, recently conducted a follow-on study to this original trial to determine how different digital interventions impacts physical activity. Their results were recently reported in the European Heart Journal – Digital Health.

After one week of collecting baseline activity information, participants were randomized into one of four one-week interventions: 1 – daily coaching based on their baseline activity patterns; 2 – daily prompts to complete 10000 steps; 3 – hourly prompts to stand following inactivity, or 4 – daily instructions to read guidelines from the American Heart Association website. The participants were then randomized again into another intervention for an additional week. The study recorded the change in mean daily step count for each of the four interventions for almost 2500 study participants.

Personalized, app-based, digital prompts can change users’ behavior and increase physical activity.

The investigators found that personalized e-coaching prompts, tailored to a user based on their baseline activity increase step count significantly by an average of over 400 steps per day: an increase of almost 10%. Two other interventions -prompts to stand after inactivity and to read AHA guidelines - also significantly increased step count (by 292 and 215 steps respectively).

This study highlights the power and utility of digital studies in general. Digital clinical trials are lower cost, can continuously recruit participants through passive enrollment, and are less labor intensive than traditional clinical trials. Digital studies also facilitate data sharing. With patient consent, the MyHeart Counts study was able to make their data for over 50000 smartphone and smartwatch users available to the scientific community.

The investigators showed that digital interventions tailored to an individual are effective in increasing short-term physical activity. Their study indicates that participants are more likely to change their behavior, and increase their physical activity, when prompts are personalized. These data highlight the promise of digital trials and emphasize the importance of precision digital medicine - tailoring digital interventions to the individual instead of applying a single therapy to all patients.

Additional Stanford Cardiovascular Institute-affiliated investigators who contributed to this study include Steven G. Hershman, Anna Shcherbina, Anders Johnson, Alexander Tolas, Jack W. O’Sullivan, Michael V. McConnell, Laura Lazzeroni, Abby C. King, Jeffrey W. Christle, Marily Oppezzo, C. Mikael Mattsson, Robert A. Harrington, and Matthew T. Wheeler.

Daniel Seung Kim, MD, PhD

Euan Ashley, MD, PhD