title: Nine months of combined training improves ex vivo skeletal muscle metabolism in individuals with type 2 diabetes.
abstract: BACKGROUND
  Type 2 diabetes (T2D) has features of disordered lipid and glucose metabolism, due in part to reduced mitochondrial content.
  
  
  OBJECTIVE
  Our objective was to investigate effects of different types of exercise on mitochondrial content and substrate oxidation in individuals with T2D (ancillary study of the randomized controlled trial Health Benefits of Aerobic and Resistance Training in Individuals with Type 2 Diabetes, HART-D).
  
  
  METHODS
  T2D individuals were randomized to aerobic training (AT, n = 12), resistance training (RT, n = 18), combination training (ATRT, n = 12), or nonexercise control (n = 10). Blood draws, peak oxygen consumption tests, dual-energy x-ray absorptiometry scans and muscle biopsies of vastus lateralis were performed before and after 9 months. Ex vivo substrate oxidations ((14)CO2), mitochondrial content, and enzyme activities were measured. Glycated hemoglobin A1c and free fatty acids were also determined.
  
  
  RESULTS
  Mitochondrial content increased after RT and ATRT. Octanoate oxidation increased after AT and ATRT, whereas palmitate, pyruvate, and acetate oxidations increased in all exercise groups. Exercise-induced responses in mitochondrial DNA were associated with improvements in peak oxygen consumption, β-hydroxyacyl-coenzyme A dehydrogenase activity, and palmitate oxidation.
  
  
  CONCLUSIONS
  Nine months of AT and RT significantly improved most aspects of skeletal muscle mitochondrial content and substrate oxidation, whereas the combination improved all aspects. These exercise responses were associated with clinical improvements, indicating that long-term training, especially combination, is an effective lifestyle therapy for individuals with T2D by way of improving muscle substrate metabolism.
authors: Translational Research Institute for Metabolism and Diabetes, Orlando, FL 32804, USA. Lauren.Sparks@flhosp.org
authors: Lauren M
authors: LM
authors: Sparks
authors: Neil M
authors: NM
authors: Johannsen
authors: Timothy S
authors: TS
authors: Church
authors: Conrad P
authors: CP
authors: Earnest
authors: Esther
authors: E
authors: Moonen-Kornips
authors: Cedric
authors: C
authors: Moro
authors: Matthijs K C
authors: MK
authors: Hesselink
authors: Steven R
authors: SR
authors: Smith
authors: Patrick
authors: P
authors: Schrauwen
mesh_terms: D000368:Aged; D001823:Body Composition; D003131:Combined Modality Therapy; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000378:metabolism* / Q000628:therapy*; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D050356:Lipid Metabolism / Q000502:physiology; D008297:Male; D008875:Middle Aged; D008931:Mitochondria, Muscle / Q000201:enzymology / Q000378:metabolism / Q000502:physiology; D018482:Muscle, Skeletal / Q000378:metabolism* / Q000473:pathology; D010806:Physical Education and Training / Q000379:methods*; D055070:Resistance Training / Q000379:methods*; D013997:Time Factors