PMID 30123136

Research
All papers

Comparing Time Efficiency of Sprint vs. High-Intensity Interval Training in Reducing Abdominal Visceral Fat in Obese Young Women: A Randomized, Controlled Trial

Tong TK, Zhang H, Shi H, Liu Y, Ai J, Nie J, Kong Z

Question

Does a time-efficient sprint interval cycling program reduce abdominal visceral fat and other body fat depots as effectively as a longer HIIT cycling program in obese young women?

Summary

In obese young women, 12 weeks of very short all-out cycling sprints and longer cycling HIIT both reduced body fat and abdominal visceral fat compared with no exercise. The sprint protocol required much less exercise time and produced a larger VO2max gain, but the longer HIIT protocol reduced abdominal subcutaneous fat and trunk fat more.

Methodology

  • Obese young female university students in China
  • 46 participants.
  • Cycle ergometer.
  • Work intervals: 6 s all-out sprint.
  • Recovery: 9 s passive recovery.
  • Intensity: All-out with progressive external load.
  • 8 min accumulated exercise plus 10-min warm-up and 5-min cool-down.
  • 3 to 4 sessions/week.
  • 12 weeks.
  • Three-arm randomized controlled trial
  • Abdominal visceral fat area, Abdominal subcutaneous fat area, and VO2max were tracked.

Outcomes

Visceral fat

SIT reduced AVFA by 6.31 cm2 and HIIT by 9.70 cm2, with no significant difference between exercise protocols.

Both exercise groups improved versus control; SIT versus HIIT not significant for AVFA.

Improved

Subcutaneous fat

Both exercise groups reduced ASFA, but SIT reduced it less than HIIT.

SIT -17.4 cm2 versus HIIT -40.7 cm2; between-exercise difference p<0.05.

Mixed

VO2max

SIT increased VO2max more than HIIT.

SIT 30.7 to 38.5 mL/kg/min; HIIT 30.2 to 34.3 mL/kg/min; between-exercise p<0.01.

Improved

Insights

  • Very short all-out intervals can change visceral fat with much lower exercise time.
  • Longer HIIT may be preferable when subcutaneous abdominal fat reduction is a goal.
  • All-out protocols need careful progression and screening.

Limitations

  • Small sample
  • Young women only
  • No objective confirmation of maximal effort in every sprint
  • Cycling laboratory protocol limits app translation
  • No long-term maintenance data

Safety

  • No adverse events occurred during testing or training.