Physical activity reconstruction is a process whereby self-trackers reflect on their physical activities and goals in an episodic fashion by recalling a series of past experiences and events. Tracking tools often include spatio-temporal cues (i.e. maps and timelines) to provide further context to these physical activity patterns, yet little is known about whether these features actually aid reflection. Here, we report a four-week user study (N=26) run with FitReconstruct, an app that fosters reconstruction of physical activity data using spatio-temporal and contextual cues to support recall of episodic information. We found that compared to a baseline version, presenting spatio-temporal and contextual cues increased the quality of reflection and user satisfaction. These findings inform design recommendations to support explicit reflective prompts in physical activity tracking apps.