This study aims to evaluate the health promotion effects of high-intensity interval training (HIIT) intervention on school-age children who are at high risk for cardiovascular disease (CVD), as well as the long-term adherence and acceptability of HIIT in this population for future application.

Evidence shows that physical activity is positively associated with cardiovascular and metabolic health in children and adolescents, including promoting lipid health, regulating blood pressure levels, and glucose metabolism. Physical activity intervention for overweight or obese children can lower body mass index, total fat mass, and abdominal fat mass, and further prevent chronic diseases such as cardiovascular and metabolic diseases. High-intensity interval training (HIIT) has been a recent research focus. Previous studies have demonstrated that HIIT can contribute to improving body composition, reducing visceral fat, and enhancing cardiovascular and pulmonary function. Moreover, compared to other trainings, HIIT is time-efficient and adaptable to various sports, thus leading to higher compliance.

However, there has been a lack of evidence regarding the intervention effects of this exercise in overweight and obese children and adolescents, and whether it can impact or even reverse cardio-metabolic risks remains unknown.

Therefore, this intervention trial might have implications and practical significance on the feasibility of promoting HIIT among this population.

Inclusion Criteria:

• Aged 7-18 years at baseline.

• At least one of the following cardio-metabolic abnormalities:

  1. Prediabetes (Impaired fasting glucose: 5.6 ≤ fasting blood glucose level ≤ 6.9 mmol/L; or Impaired glucose tolerance: 7.8 ≤ blood glucose level after 2 hours postprandial ≤ 11.0 mmol/L).
  2. Lipid abnormalities (High-density lipoprotein cholesterol ≤ 1.04 mmol/L; or Low-density lipoprotein cholesterol ≥ 3.37 mmol/L; or Triglycerides ≥ 1.70 mmol/L, or Total cholesterol ≥ 5.18 mmol/L).
  3. Elevated blood pressure (Systolic/diastolic blood pressure consistently higher than the 90th percentile for gender, age, and height; or systolic/diastolic blood pressure ≥ 120/80 mmHg).

• Written consent from participants and their guardians.

Exclusion Criteria:

• Previously diagnosed with heart failure, severe malnutrition, immune deficiency, liver or kidney disease, cancer, or other diseases deemed unsuitable for participation.
• Taking weight loss drugs, or undergone weight loss surgery.
• Attending behavior-based intervention programs (exercise or diet) within a year.
• Regular HIIT (at least once per week).
• Secondary obesity, such as neuropsychiatric disorders, endocrine disorders, sleep apnea syndrome, or other conditions.
• Unable to take interventions due to health conditions, such as joint diseases, fractures, injuries.
• Other situations unsuitable for participation.