PMID 37360303

Research
All papers

High-intensity interval training prevents muscle mass loss in overweight Chilean young adults during a hypocaloric-Mediterranean diet: a randomized trial

Monsalves-Álvarez M, Jiménez T, Bunout D, Barrera G, Hirsch S, Sepúlveda-Guzman C, Silva C, Rodriguez JM, Troncoso R, de la Maza MP

Question

Does adding supervised HIIT to a hypocaloric Mediterranean diet improve body composition and metabolic outcomes compared with diet alone or HIIT alone in overweight or obese adults?

Summary

In overweight and obese Chilean adults, a hypocaloric Mediterranean diet produced the most weight and fat loss but also reduced lean mass. Adding supervised cycling HIIT appeared to attenuate lean-mass loss during dieting, while HIIT alone did little for weight or fat loss. Adherence was poor, with only 41 of 83 randomized participants included in the per-protocol analysis.

Methodology

  • Overweight or obese Chilean adults
  • 41 participants.
  • Static bicycle HIIT.
  • Work intervals: 1 min.
  • Recovery: 1 min rest cycling at 50 W.
  • Intensity: 75% peak power, intended 85% to 90% HRmax.
  • 25 min.
  • 3 sessions/week.
  • 3 months.
  • Randomized 3-month intervention trial analyzed per protocol
  • Lean body mass, Fat mass, and VO2peak were tracked.

Outcomes

Lean mass

Diet alone reduced lean mass, while exercise arms attenuated or prevented this loss.

DEXA total lean body mass percent change: MD -2.8 +/- 2.8%, EX -0.1 +/- 2.3%, MD+EX -0.6 +/- 2.1%; p=0.0153.

Improved

Weight

Diet groups lost weight, but exercise alone did not.

MD -7.2 +/- 3.6%, EX -0.6 +/- 3.2%, MD+EX -5.3 +/- 2.7%; p<0.0001.

Mixed

Metabolic markers

Glucose, insulin, HOMA-IR, and lipids did not differ significantly despite body-composition changes.

Between-group p values for glucose, insulin, HOMA-IR, and lipids were >0.05.

No clear change

Insights

  • HIIT may be useful to preserve lean mass during calorie restriction.
  • Do not attribute diet-driven fat loss to HIIT alone.
  • Adherence support is crucial because retention was about half.

Limitations

  • Small per-protocol sample
  • Low adherence/retention
  • Short intervention
  • No sex-specific analysis
  • Protein intake not fully ascertained

Safety

  • The training method was described as well tolerated.
  • No explicit adverse-event details were found in the extracted NXML.