PMID 36231972

Research
All papers

Effect of Sprint Interval Training on Cardiometabolic Biomarkers and Adipokine Levels in Adolescent Boys with Obesity

Salus M, Tillmann V, Remmel L, Unt E, Mäestu E, Parm Ü, Mägi A, Tali M, Jürimäe J

Question

Does 12 weeks of supervised all-out cycling sprint interval training improve cardiometabolic biomarkers, adipokines, and fitness in adolescent boys with obesity compared with a control group maintaining habitual lifestyle?

Summary

In adolescent boys with obesity, 12 weeks of supervised cycling sprint interval training improved cardiorespiratory fitness and produced a favorable between-group LDL cholesterol signal, but most metabolic biomarkers and adipokines did not improve relative to a non-exercising control group.

Methodology

  • Adolescent boys diagnosed with childhood obesity, recruited from Tartu City and County, Estonia.
  • 28 participants.
  • Electronically braked cycle ergometer.
  • Work intervals: 30 seconds all-out cycling.
  • Recovery: 4 minutes active rest after each sprint.
  • Intensity: All-out effort with target cadence at least 90 rpm; heart rate monitored with Polar H7.
  • 10-minute warm-up, sprint/rest block, and 5-minute cool-down.
  • 3 sessions per week on non-consecutive weekdays.
  • 12 weeks.
  • Controlled 12-week exercise intervention with pre/post testing; group allocation was described as distribution into SIT and control groups but randomization was not clearly stated.
  • VO2peak, Body composition, Lipids and glucose-insulin markers, and Adipokines were tracked.

Outcomes

VO2peak

SIT improved cardiorespiratory fitness compared with control, including relative VO2peak per body mass and lean body mass.

Between-group change: absolute VO2peak p = 0.044, VO2peak/kg p = 0.004, VO2peak/lean body mass p < 0.001.

Improved

LDL cholesterol

LDL-c change was favorable for SIT compared with control.

Marginal change SIT -0.06 +/- 0.1 vs control +0.19 +/- 0.1 mmol/L; p = 0.025, eta2 = 0.19.

Improved

Body fat

No significant between-group body composition difference was reported, but body fat percentage decreased within the SIT group.

SIT body fat percentage 41.1 +/- 1.3 to 39.2 +/- 1.5; within-group p = 0.006.

Mixed

Glucose, insulin, HOMA-IR, leptin, adiponectin

Most measured cardiometabolic and adipokine markers did not show meaningful SIT-specific improvements.

No significant group differences for fasting glucose, insulin, HOMA-IR, leptin, or adiponectin.

No clear change

Insights

  • A low-volume cycling SIT program can improve fitness in adolescent boys with obesity when closely supervised.
  • A 4-to-6 sprint progression over 12 weeks is a concrete dose model for youth cycling SIT.
  • Metabolic biomarker changes were limited, so fitness gains should not be presented as broad cardiometabolic normalization.

Limitations

  • Small final analyzed sample.
  • Randomization was unclear.
  • Secondary analysis from a larger parent study and no a priori sample-size calculation for these outcomes.
  • No caloric restriction or controlled diet.
  • Boys only, limiting sex generalizability.
  • Cycle ergometer all-out sprints may not translate directly to unsupervised bodyweight HIIT.

Safety

  • Sessions were supervised and heart rate monitored.
  • The article did not report specific adverse events.
  • Attendance was at least 80%.