PMID 27368057

Research
All papers

Comparison of High-Intensity Interval Training and Moderate-to-Vigorous Continuous Training for Cardiometabolic Health and Exercise Enjoyment in Obese Young Women: A Randomized Controlled Trial

Kong Z, Fan X, Sun S, Song L, Shi Q, Nie J

Question

How do 5 weeks of low-volume cycling HIIT and moderate-to-vigorous continuous cycling compare for cardiometabolic outcomes, sex hormones, and exercise enjoyment in obese young women?

Summary

In sedentary obese young women, 5 weeks of low-volume cycling HIIT improved VO2peak about as much as much longer moderate-to-vigorous continuous cycling and was more enjoyable. Continuous training produced clearer within-group reductions in body mass and fat measures, while HIIT mostly maintained body weight. Neither training mode improved blood lipids, and the trial lacked a no-exercise control.

Methodology

  • Sedentary obese young women.
  • 31 participants.
  • Cycle ergometer.
  • Work intervals: 8 s sprinting.
  • Recovery: 12 s passive rest.
  • Intensity: Sprint as hard as possible; initial resistance 1.0 kg with progression.
  • About 26 min including warm-up/cool-down.
  • 4 sessions/week.
  • 5 weeks.
  • Two-arm randomized controlled training trial without no-exercise control.
  • VO2peak, Body composition, Blood lipids and sex hormones, and Exercise enjoyment were tracked.

Outcomes

VO2peak

Both HIIT and MVCT increased VO2peak by about 10%.

HIIT +9.1%, MVCT +10.3%, p = .010, partial eta2 = .41.

Improved

Body composition

MVCT reduced body water, fat mass, and percent body fat within group; no clear adjusted between-group advantage.

MVCT TBW -1.8% p = .034; FM -4.7% p = .002; PBF -2.9% p = .016.

Mixed

Blood lipids

Neither group had favorable lipid changes.

No clear change

Enjoyment

HIIT was more enjoyable than MVCT.

First two sessions PAES 65 +/- 10 HIIT vs 45 +/- 17 MVCT, p = .001.

Improved

Insights

  • Micro-interval cycling can improve fitness with less time and higher enjoyment than continuous cycling.
  • Weight/fat-loss claims should be modest for a 5-week HIIT dose.
  • Enjoyment can be measured repeatedly as a product signal.

Limitations

  • Small sample.
  • No no-exercise control.
  • Short 5-week intervention.
  • Menstrual phase and possible PCOS not fully controlled.
  • BIA body composition.
  • Cycling protocol not directly bodyweight-translatable.
  • No detailed adverse-event reporting.

Safety

  • No adverse-event details were reported.
  • Participants required medical clearance for vigorous exercise.