“Run Forrest Run!” : Measuring the Impact of App-Enabled Performance and Social Feedback on Athletic and Usage Outcomes

Exercise-tracking apps are novel tools for delivering personalized behavioral interventions. Despite the growing usage of exercise applications, the efficacy of in-exercise app features in driving usage and athletic outcomes remains to be poorly understood. Drawing on the literature on motivation, this study examines two specific forms of such in-exercise interventions, namely performance feedback and social feedback. We conducted an 18-month-long field study, with 1,037 uniformed group servicemen, to assess the effect of these feedback types on running and usage outcomes. Results from the field study provided evidence that these two app features improved the running times and frequency of application usage of the servicemen, on average. Contrary to the common belief that more features are better, we find that the two feedback features when offered jointly produce non-additive effects. We traced this absence of additive effects to arise from the out-exercise feedback presented to users who also received performance feedback. Subsequent tests at more granular levels reveal that users who received both feedback types in exercise episodes exhibit overconfidence behavior by participating in fewer subsequent exercises. Heterogeneity tests revealed that users who have not run many 5k runs previously benefited from any feedback received, but users who were avid 5k runners would not benefit from the usage of the social feedback feature. The results further indicate that performance feedback generated a slow but sustained increase in usage frequency, while social feedback spurred quick initial growth in usage but dwindled in effectiveness over time. Implications for theory and practice, as well as directions for further research, are discussed