PMID 35232402

Research
All papers

Effects of school-based high-intensity interval training on body composition, cardiorespiratory fitness and cardiometabolic markers in adolescent boys with obesity: a randomized controlled trial

Meng C, Yucheng T, Shu L, Yu Z

Question

Can school-based running HIIT improve body composition, cardiorespiratory fitness, and cardiometabolic markers in boys with obesity compared with MICT and control?

Summary

This randomized school-based trial compared 12 weeks of short running HIIT, 30-minute moderate continuous running, and usual behavior in Chinese boys with obesity. HIIT and MICT both improved BMI, fat mass, cardiorespiratory fitness, and HOMA-IR, but HIIT produced a larger VO2peak increase and reduced visceral adipose tissue and LDL. The HIIT sessions required far less weekly training time than MICT.

Methodology

  • Adolescent boys with obesity.
  • 45 participants.
  • Outdoor track running.
  • Work intervals: 15 seconds at 90-100% MAS.
  • Recovery: 15 seconds at 50% MAS; 3-minute rest between two sets.
  • Intensity: 90% MAS weeks 1-4, 95% MAS weeks 5-8, 100% MAS weeks 9-12; about 80-90% HRmax.
  • 11-minute HIIT block, plus 5-minute warm-up and cooldown.
  • 3 sessions/week.
  • 12 weeks.
  • Parallel-group randomized controlled trial with HIIT, MICT, and non-exercising control groups.
  • Body composition, Cardiorespiratory fitness, Insulin resistance, and Lipids were tracked.

Outcomes

Body composition

BMI and fat mass decreased in both HIIT and MICT; visceral adipose tissue decreased significantly in HIIT, while body fat percentage decreased in MICT.

BMI: HIIT -1.8 kg/m2 and MICT -1.2 kg/m2, p<0.01; FM: HIIT -1.6 kg p<0.05, MICT -3.7 kg p<0.01; VAT HIIT -53 g vs -17 g, p<0.01.

Improved

VO2peak

VO2peak improved in both exercise groups, with a significantly larger increase in HIIT.

HIIT +6.0 to 6.1 mL/kg/min vs MICT +3.8 mL/kg/min, p<0.01.

Improved

HOMA-IR

HOMA-IR improved in both HIIT and MICT, with no significant difference between exercise groups.

HIIT -27.3% and MICT -28.6%, p<0.05.

Improved

LDL cholesterol

LDL decreased only in the HIIT group.

LDL -17.2%, p<0.05.

Improved

Other cardiometabolic markers

No significant changes were found in other cardiometabolic markers; DBP did not significantly change within intervention groups but was lower than control post-intervention.

Authors report no significant change in other cardiometabolic markers.

Mixed

Insights

  • A very short MAS-paced 15/15 running protocol can improve fitness in boys with obesity.
  • Compared with MICT, HIIT achieved similar or better outcomes with much less session time.
  • Some participants initially struggled to hit prescribed distances, so pacing should be adaptive.

Limitations

  • Small sample and boys only.
  • Some students refused participation, creating potential selection bias.
  • No daily physical activity diary/accelerometer for all participants.
  • Running intensity on track was difficult to measure and monitor precisely.
  • Maturation during intervention may have influenced outcomes.
  • Adverse events were not clearly reported.

Safety

  • Adverse events were not explicitly reported in the paper.
  • Participants with medical conditions or contraindications were excluded.