NCT07338058

High-Intensity Exercise Snacks for Reducing Mobile Phone Addiction in Adolescents

Effect of Fragmented Exercise Snacks on Mobile Phone Addiction and Psychophysical Health in Adolescents: A Randomized Controlled Trial

• Status: Completed
• Phase: N/A
• Study type: Interventional
• Enrollment: 386 (actual)
• Sponsor: Jinan University Guangzhou · Academic / Other
• Sex: All
• Age: 12 Years – 18 Years
• Healthy volunteers: Not accepted

Summary

This study is a randomized controlled trial (RCT) designed to evaluate the long-term effectiveness of "Exercise Snacks" (fragmented, high-intensity bouts of exercise) in reducing mobile phone addiction among adolescents. Participants will be randomly assigned to either an intervention group or a control group. The intervention spans 5 months and is followed by a 1-month follow-up period (Month 6). The intervention group will perform short bursts of exercise (e.g., 1-minute sprints, squats) multiple times daily during school breaks. The program is divided into three progressive phases: adaptation, enhancement, and consolidation. The study aims to determine whether this sustained "snack-style" exercise regimen can significantly lower mobile phone addiction scores, improve physical fitness, and enhance psychological traits such as self-control and resilience over a semester-long period.

Detailed description

Background and Rationale: Adolescents face increasing risks of mobile phone addiction, which is associated with sedentary behavior. "Exercise Snacks"-isolated bouts of vigorous exercise performed periodically throughout the day-offer a time-efficient solution. This study applies the COMB model and Self-Determination Theory to a long-term, semester-based intervention. Study Design: This is a single-blind, randomized controlled trial conducted over a 6-month period (5 months of intervention + 1 month of follow-up). Intervention Protocol: The intervention group follows a progressive "Exercise Snacks" program: Adaptation Phase (Month 1 / Weeks 1-4): Focus on habit formation. Participants perform "Sprint Snacks" (e.g., stair climbing) 3 times daily and "Strength Snacks" (e.g., squats) 2 times weekly. Intensity is monitored to ensure safety and correct posture. Enhancement Phase (Months 2-3 / Weeks 5-12): Focus on physiological adaptation. Frequency increases to 4 daily Sprint Snacks and 3 weekly Strength Snacks. A weekly collective High-Intensity Interval Training (HIIT) session is introduced to maximize cardiorespiratory benefits. Consolidation Phase (Months 4-5 / Weeks 13-20): Focus on psychological integration. Daily snacks continue. Collective HIIT sessions increase to twice weekly. A cognitive-behavioral guidance component is added (bi-weekly) to help students identify phone use triggers and internalize healthy behaviors. Follow-up Phase (Month 6 / Weeks 21-24): The structured intervention ceases. Participants are encouraged to maintain self-guided exercise. Final assessments are conducted at the end of Month 6 to evaluate the retention of intervention effects and any "rebound" in mobile phone addiction. Outcome Measures: The primary outcome is Mobile Phone Addiction (SAS-SV), assessed at baseline, Month 3, Month 5 (post-intervention), and Month 6 (follow-up). Secondary outcomes include physical activity levels (PARS-3 and wearables), self-control (BSCS), resilience (RSCA), and mental health status.

Conditions

• Smartphone Addiction
• Sedentary Behaviors
• Adolescent Behavior

Interventions

Type	Name	Description
BEHAVIORAL	Exercise Snacks Protocol	The intervention consists of a structured 5-month "Exercise Snacks" program. Participants perform "snacks"-defined as isolated bouts of vigorous-intensity physical activity (\<2 min)-distributed 3-4 times throughout the school day during breaks. Content: The regimen includes "Sprint Snacks" (e.g., stair climbing, high knees) and "Strength Snacks" (e.g., squats, push-ups). Intensity: Participants are instructed to reach a subjective effort level of Borg RPE \> 14 (Somewhat Hard to Hard). Progression: The program follows a phased approach: Adaptation (Month 1): Focus on habit formation and movement quality. Enhancement (Months 2-3): Increased frequency and inclusion of weekly collective HIIT sessions. Consolidation (Months 4-5): Integration of cognitive-behavioral guidance to replace mobile phone usage habits.

Timeline

• Start date: 2025-09-01
• Primary completion: 2026-03-01
• Completion: 2026-03-01
• First posted: 2026-01-13
• Last updated: 2026-04-09

Locations

1 site across 1 country: Hong Kong