An interventional study of Exercise Snacks Protocol in Smartphone Addiction, Sedentary Behaviors and Adolescent Behavior, sponsored by Jinan University Guangzhou. Completed at 1 site in Hong Kong. Open to participants aged 12 Years to 18 Years. Per ClinicalTrials.gov, last updated 2026-04-30.
Sponsored by Jinan University Guangzhou · Not applicable, Interventional, and Treatment
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.
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.
166 studies on the registry are indexed under Internet Addiction Disorder; 47 are open to participants now.
This study's enrollment of 386 is above the median of 88 across 96 interventional studies indexed under Internet Addiction Disorder.
Browse Internet Addiction Disorder studies →Jinan University Guangzhou is the lead sponsor of 14 studies on the registry; 2 are open to participants now.
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Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants in this group follow a 5-month structured "Exercise Snacks" protocol. The intervention consists of daily short bursts of high-intensity exercise (e.g., 1-minute sprints, squats) performed during school breaks, supplemented by weekly collective HIIT sessions. The program progresses through adaptation, enhancement, and consolidation phases.
Behavioral: Exercise Snacks Protocol
Participants in this group are instructed to maintain their usual daily campus life and academic routines without altering their existing physical activity habits. They do not participate in the structured exercise snacks program during the study period.
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.
Also known as: Fragmented High-Intensity Exercise
Change in Mobile Phone Addiction Severity (assessed by SAS-SV)
The severity of mobile phone addiction is measured using the Smartphone Addiction Scale-Short Version (SAS-SV). This self-report scale consists of 10 items. Each item is rated on a 6-point Likert scale ranging from 1 ("Strongly Disagree") to 6 ("Strongly Agree"). The total score is calculated by summing the scores of all 10 items, resulting in a range from 10 to 60. Higher scores indicate a higher level of mobile phone addiction risk.
Time frame: Baseline, Month 3, Month 4, and Month 6
Psychological Resilience(CD-RISC-10 Score)
Psychological resilience is assessed using the Child and Youth Resilience Measure (CYRM). Higher scores indicate greater resilience.
Time frame: Baseline, Month 2, Month 4, and Month 6
Self-Control Capacity (BSCS Score)
13 items, 1-5 scale. Range 13-65. Higher scores indicate better self-control.
Time frame: Baseline, Month 2, Month 4, and Month 6.
Objectively Measured Sleep Parameters via Wrist-Worn Accelerometer
Sleep parameters are continuously monitored using a consumer-grade wrist-worn accelerometer (Xiaomi Mi Band) for 7 consecutive days at each assessment time point. Primary sleep outcomes include total sleep time (TST), sleep onset latency (SOL), wake after sleep onset (WASO), and sleep efficiency (SE). Data are extracted from the device via the companion application and processed to derive nightly averages across the 7-day monitoring period. Participants are instructed to wear the device 24 hours per day, removing it only during water-based activities if the device is not waterproof.
Time frame: Baseline, Month 3, Month 5, and Month 6
Objectively Measured Daily Physical Activity via Wrist-Worn Accelerometer
Daily physical activity is continuously monitored using a consumer-grade wrist-worn accelerometer (Xiaomi Mi Band) for 7 consecutive days at each assessment time point. Outcomes include daily step count, duration of moderate-to-vigorous physical activity (MVPA), light physical activity, and sedentary time. Data are extracted from the device via the companion application and averaged across valid wear days (defined as ≥10 hours of wear time per day, with a minimum of 4 valid days required).
Time frame: Baseline, Month 2,Month 4, and Month 6
Psychological Distress (DASS-21 Score)
Psychological distress is assessed using the Depression Anxiety Stress Scales-21 (DASS-21). The scale measures symptoms of depression, anxiety, and stress over the past week. Higher scores indicate greater psychological distress.
Time frame: Baseline, Month 2, Month 4, and Month 6
Well-Being (WHO-5 Score)
Well-being is assessed using the WHO-5 Well-Being Index. Higher scores indicate better well-being.
Time frame: Baseline, Month 2, Month 4, and Month 6
Basic Psychological Need Satisfaction (SDT Score)
Basic psychological need satisfaction is assessed using a self-determination theory-based scale. Higher scores indicate greater basic psychological need satisfaction.
Time frame: Baseline, Month 2, Month 4, and Month 6
Emotion Regulation: Cognitive Reappraisal (ERQ Score)
Cognitive reappraisal is assessed using the Emotion Regulation Questionnaire (ERQ). Higher scores indicate greater use of cognitive reappraisal.
Time frame: Baseline, Month 2, Month 4, and Month 6
Emotion Regulation: Expressive Suppression (ERQ Score)
Expressive suppression is assessed using the Emotion Regulation Questionnaire (ERQ). Higher scores indicate greater use of expressive suppression.
Time frame: Baseline, Month 2, Month 4, and Month 6
Plan to share: Yes — De-identified individual participant data (IPD) that underlie the results reported in the article will be shared. This includes the text, tables, figures, and appendices. Data will be anonymized to protect participant privacy.
Supporting information: Study protocol, Statistical analysis plan, Analytic code
Time frame: Beginning 3 months following article publication and ending 5 years following article publication.
Access criteria: Data will be available to researchers who provide a methodologically sound proposal for meta-analysis or verification purposes. Proposals should be directed to the Principal Investigator at penny@link.cuhk.edu.hk. To gain access, data requestors will need to sign a data access agreement.
No publications or documents are linked to this record.
Ran from Sep 2025 to primary completion in Mar 2026, 6 months.
Of 72 non-industry interventional studies with no phase under Internet Addiction Disorder, half reached primary completion within 6 months of starting (the median), counting those still running; a quarter within 3 and three quarters within 10. This study's 6 months is close to that.
Counting every sponsor, half of 72 studies reached it within 6 months; a quarter within 3 and three quarters within 10.
How these figures are worked out, and which studies are left out of them.
This study is completed, as verified in Apr 2026. You cannot join it, but the record below documents what was studied.
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Jinan University Guangzhou