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Interval training in the fed or fasted state improves body composition and muscle oxidative capacity in overweight women
Author(s) -
Gillen Jenna B.,
Percival Michael E.,
Ludzki Alison,
Tarnopolsky Mark A.,
Gibala Martin. J.
Publication year - 2013
Publication title -
obesity
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.438
H-Index - 199
eISSN - 1930-739X
pISSN - 1930-7381
DOI - 10.1002/oby.20379
Subject(s) - overweight , medicine , endocrinology , glycemic , citrate synthase , interval training , insulin , zoology , obesity , chemistry , biology , biochemistry , enzyme
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 , VO 2peak : 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.