Format

Send to

Choose Destination
Am J Physiol Endocrinol Metab. 2012 Dec 15;303(12):E1440-5. doi: 10.1152/ajpendo.00355.2012. Epub 2012 Oct 9.

Effect of exercise training on metabolic flexibility in response to a high-fat diet in obese individuals.

Author information

1
Department of Kinesiology, College of Health and Human Performance, East Carolina University, Greenville, NC 27858, USA.

Abstract

Obese individuals typically exhibit a reduced capacity for metabolic flexibility by failing to increase fatty acid oxidation (FAO) upon the imposition of a high-fat diet (HFD). Exercise training increases FAO in the skeletal muscle of obese individuals, but whether this intervention can restore metabolic flexibility is unclear. The purpose of this study was to compare FAO in the skeletal muscle of lean and obese subjects in response to a HFD before and after exercise training. Twelve lean (means ± SE) (age 21.8 ± 1.1 yr, BMI 22.6 ± 0.7 kg/m²) and 10 obese men (age 22.4 ± 0.8 yr, BMI 33.7 ± 0.7 kg/m²) consumed a eucaloric HFD (70% of energy from fat) for 3 days. After a washout period, 10 consecutive days of aerobic exercise (1 h/day, 70% V(O₂(peak))) were performed, with the HFD repeated during days 8-10. FAO and indices of mitochondrial content were determined from muscle biopsies. In response to the HFD, lean subjects increased complete FAO (27.3 ± 7.4%, P = 0.03) in contrast to no change in their obese counterparts (1.0 ± 7.9%). After 7 days of exercise, citrate synthase activity and FAO increased (P < 0.05) regardless of body habitus; addition of the HFD elicited no further increase in FAO. These data indicate that obese, in contrast to lean, individuals do not increase FAO in skeletal muscle in response to a HFD. The increase in FAO with exercise training, however, enables the skeletal muscle of obese individuals to respond similarly to their lean counterparts when confronted with short-term excursion in dietary lipid.

PMID:
23047988
PMCID:
PMC3532462
DOI:
10.1152/ajpendo.00355.2012
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Atypon Icon for PubMed Central
Loading ...
Support Center