Interval training in the fed or fasted state improves body composition and muscle oxidative capacity in overweight women

Obesity (Silver Spring). 2013 Nov;21(11):2249-55. doi: 10.1002/oby.20379. Epub 2013 May 31.


Objective: To investigate the effects of low-volume high-intensity interval training (HIT) performed in the fasted (FAST) versus fed (FED) state on body composition, muscle oxidative capacity, and glycemic control in overweight/obese women.

Design and methods: Sixteen women (27 ± 8 years, BMI: 29 ± 6 kg/m(2) , VO2peak : 28 ± 3 ml/kg/min) were assigned to either FAST or FED (n = 8 each) and performed 18 sessions of HIT (10× 60-s cycling efforts at ∼90% maximal heart rate, 60-s recovery) over 6 weeks.

Results: There was no significant difference between FAST and FED for any measured variable. Body mass was unchanged following training; however, dual energy X-ray absorptiometry revealed lower percent fat in abdominal and leg regions as well as the whole body level (main effects for time, P ≤ 0.05). Fat-free mass increased in leg and gynoid regions (P ≤ 0.05). Resting muscle biopsies revealed a training-induced increase in mitochondrial capacity as evidenced by increased maximal activities of citrate synthase and β-hydroxyacyl-CoA dehydrogenase (P ≤ 0.05). There was no change in insulin sensitivity, although change in insulin area under the curve was correlated with change in abdominal percent fat (r = 0.54, P ≤ 0.05).

Conclusion: Short-term low-volume HIT is a time-efficient strategy to improve body composition and muscle oxidative capacity in overweight/obese women, but fed- versus fasted-state training does not alter this response.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adipose Tissue / metabolism
  • Adipose Tissue / pathology
  • Adult
  • Body Composition*
  • Diet, Reducing
  • Eating / physiology*
  • Exercise Therapy / methods*
  • Fasting / metabolism*
  • Female
  • Humans
  • Muscle, Skeletal / metabolism*
  • Overweight / metabolism*
  • Overweight / therapy*
  • Oxidation-Reduction
  • Weight Reduction Programs
  • Young Adult