Effects of Aerobic Exercise and High-Intensity Interval Training on the Mental Health of Adolescents Living in Poverty: Protocol for a Randomized Controlled Trial

Background: The increasing rate of mental health issues among adolescents has recently been a considerable concern in Hong Kong. In particular, adolescents with low socioeconomic status (SES) are likely to experience poor mental health, including low self-esteem and high levels of anxiety, anger, and depression. Previous research has found that physical activities have a positive impact on improving mental health outcomes among adolescents. However, approximately 96% of adolescents in Hong Kong do not engage in regular exercise, which potentially increases the risk of poor mental health. Objective: In this study, we aim to examine whether changes in the 3 indicators (reduced ill-being, enhanced well-being, and cognitive functions) of mental health among adolescents with low SES are evident before and after exercise. In addition, this study compares the effectiveness of aerobic exercise and high-intensity interval training on these indicators among adolescents with low SES. Methods: A total of 78 participants from low-income families aged between 12 and 15 years from 3 to 4 secondary schools will be recruited for this study. They will be randomly assigned to either an aerobic exercise group (26/78, 33%), a high-intensity interval training group (26/78, 33%), or a control group (26/78, 33%). Participants in the first 2 groups will take part in a 10-week training program period. Participants in the control group will participate in other physical activities during the same intervention period. The training sessions will be conducted 3 times per week on nonconsecutive days. A range of neuropsychological tests and psychometric scales will be used to measure the executive functions and indicators of psychological well-being and ill-being, including enjoyment, self-efficacy, mood, depression, anxiety, and stress at pretest, posttest, and follow-up assessments. Results: The project was funded in 2021 by the Research Matching Grant Scheme, through the University Grants Committee of the Hong Kong Special Administrative Region Government. Ethical approval has been obtained from the author's institution. Participant recruitment will begin in January 2022 and continue through to April 2022. Data collection and follow-up are expected to be completed by the end of 2022. The results are expected to be submitted for publication in 2023. Conclusions: The findings will help inform policy makers and practitioners in promoting the importance of physical exercise to enhance mental health.