This paper explores the effect of feedback presentation formats in mobile fitness apps. Drawing from computers are social actors (CASA) paradigm, cognitive load theory (CLT), and social presence literature in this study, we conceptualize that when a user is involved in different types of exercise (aerobic or anaerobic) the exposure to more humanized feedback can create differential influence in user’s cognitive load and user engagement. This differential influence subsequently affects the fitness performance of the user. This conceptualization will be validated through an experiment. The outcomes of this study can help fitness app developers to design effective fitness apps. Similarly the findings can assist users in choosing the most appropriate fitness app that can enhance their fitness.