Exercise apps and fitness trackers have become very popular, but do they really help users become more active? In a study involving 210 inactive women, researchers observed that those who used the combination of an exercise app, an activity tracker, and personal counseling increased the number of steps they took per day, as well as the number of minutes per day they engaged in moderate-to-vigorous physical activity—and these increases persisted up to three months after the end of the study! JAMA Network Open, May 2019