Physical activity trackers rely on fixed daily step goals, treating the day as the primary unit for planning and evaluating activity. However, these goals often misalign with everyday life: schedules fluctuate, opportunities for movement vary, and long-term targets can be difficult to sustain, leading to frustration and disengagement. Despite growing evidence that short bouts of movement can meaningfully improve health, current systems provide limited support for acting on these brief, situated opportunities. This paper investigates micro-goals (i.e., brief, situated goals) as an alternative framing for supporting physical activity. We developed Mikro, a smartwatch app enabling on-the-go micro-goal setting, and deployed it in a 27-day field study with 16 participants. Our findings show that micro-goals encouraged frequent tailoring, supported immediate action, and helped participants capitalize on small opportunities for movement. We argue that micro-goals can complement daily step targets by scaffolding more flexible, adaptive, and engaging ways of staying active.
ACM CHI Conference on Human Factors in Computing Systems