Interval training in the fed or fasted state improves body composition and muscle oxidative capacity in overweight women. (31st May 2013)

• Record Type: Journal Article
• Authors: Gillen, Jenna B.; Percival, Michael E.; Ludzki, Alison; Tarnopolsky, Mark A.; Gibala, Martin. J.
• Is Part Of: Obesity. Volume 21:Number 11(2013:Nov.)
• Page Start: 2249
• Page End: 2255
• Publication Date: 2013-05-31
• Subjects: Obesity -- Periodicals; 616.398005
• DOI: 10.1002/oby.20379
• Languages: English
• ISSNs: 1930-7381

Abstract

Abstract : 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.