Physical Activity and Mental Health
Promoting physical activity is widely recognized as effective for treating and preventing depression and anxiety.
Previous studies demonstrate that maintaining high physical activity levels reduces the risk of developing depression by approximately 20%. The standard benchmark for "high physical activity" is often defined as engaging in at least 150 minutes per week of moderate-to-vigorous activity (activities slightly raising heart rate, equal to or above walking intensity). However, even shorter durations help improve depressed mood and anxiety, provided activity time is maximized whenever possible.
Particularly, leisure-time physical activity shows a stronger association with mood improvement compared to occupational or transport-related activity, making it highly recommended for stress relief and fulfillment. Conversely, work-related physical activity may not contribute to mood improvement and could potentially impose a physical or mental burden.
In our 2026 validation paper (Item 5 in the publication list above), we reported findings from a randomized controlled trial evaluating the effectiveness of the app.
Key Findings
- Demonstrated Mental Health Benefits of a Standalone Smartphone App Intervention: Using "ASHARE"—an app that passively (automatically) monitors physical activity such as step count along with mental health—led to a significant reduction in psychological distress after three months of use.
- Greater Efficacy in Individuals with Initially Lower Distress: The app's benefits were more pronounced among participants with lower baseline levels of psychological distress (K6 Japanese version [※] score below 5), demonstrating its potential to suppress increases in psychological distress.
※ K6 Japanese version: A validated and reliable screening scale used to assess psychological distress. A score of 5 or higher is recognized as the cutoff point for clinically significant psychological distress.
- Short-Term and Modest Effects: The reduction in psychological distress was modest, and distress levels returned to baseline after participants discontinued app usage. Sustaining long-term benefits will require strategies to promote continuous engagement.
Study Details & Results
In this study, we conducted a randomized controlled trial involving 793 Japanese workers to evaluate the effectiveness of the ASHARE app. Participants were randomly assigned to either the intervention group (397 participants who used the ASHARE app for three months) or the control group (396 participants who received an informational booklet on stress management). Changes in psychological distress and physical activity levels were subsequently monitored.
At the 3-month follow-up, the app-intervention group showed a 0.56-point decrease in psychological distress scores compared to the control group, representing a statistically significant difference between the two groups.
Furthermore, stratified analysis based on baseline psychological distress levels revealed that the app was more effective among individuals with low initial distress (K6 Japanese version score < 5). For this group, using the app successfully mitigated the increase in psychological distress at the 3-month mark compared to the control group.
Future Directions
This study demonstrates that passive monitoring of physical activity and psychological distress via a smartphone app holds promise for primary prevention—preventing mental health issues before they arise among working populations.
However, the reduction in psychological distress was modest, meaning users might not clearly perceive the benefits on an individual level. Additionally, during the optional-use period from months 3 to 6, app retention dropped sharply, and the distress-reducing effect disappeared by month 6. Because continuous app usage is essential to sustain benefits, future research must explore strategies to boost long-term engagement. Furthermore, app usage did not produce a measurable increase in physical activity levels, leaving the underlying mechanism of distress improvement unconfirmed. More objective and precise physical activity measurements will be needed to clarify these mechanisms.
Naturally, continuously enhancing the core features and quality of the app itself is also paramount. We will continue refining ASHARE's prediction accuracy and expanding its functional capabilities.