Disclosure: No conflict declared for all authors.
Interval training in the fed or fasted state improves body composition and muscle oxidative capacity in overweight women
Article first published online: 31 MAY 2013
Copyright © 2013 The Obesity Society
Volume 21, Issue 11, pages 2249–2255, November 2013
How to Cite
Gillen, J. B., Percival, M. E., Ludzki, A., Tarnopolsky, M. A. and Gibala, Martin. J. (2013), Interval training in the fed or fasted state improves body composition and muscle oxidative capacity in overweight women. Obesity, 21: 2249–2255. doi: 10.1002/oby.20379
- Issue published online: 1 NOV 2013
- Article first published online: 31 MAY 2013
- Accepted manuscript online: 1 FEB 2013 02:00AM EST
- Manuscript Accepted: 18 DEC 2012
- Manuscript Received: 19 SEP 2012
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/m2, 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.
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).
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.