title: High-intensity knee extensor training restores skeletal muscle function in COPD patients.
abstract: Improving reduced skeletal muscle function is important for optimising exercise tolerance and quality of life in chronic obstructive pulmonary disease (COPD) patients. By applying high-intensity training to a small muscle group, we hypothesised a normalisation of muscle function. Seven patients with COPD performed 6 weeks (3 days·week(-1)) of high-intensity interval aerobic knee extensor exercise training. Five age-matched healthy individuals served as a reference group. Muscle oxygen uptake and mitochondrial respiration of the vastus lateralis muscle were measured before and after the 6-week training programme. Initial peak work and maximal mitochondrial respiration were reduced in COPD patients and improved significantly after the training programme. Peak power and maximal mitochondrial respiration in vastus lateralis muscle increased to the level of the control subjects and were mainly mediated via improved complex I respiration. Furthermore, when normalised to citrate synthase activity, no difference in maximal respiration was found either after the intervention or compared to controls, suggesting normal functioning mitochondrial complexes. The present study shows that high-intensity training of a restricted muscle group is highly effective in restoring skeletal muscle function in COPD patients.
authors.affiliation: Dept of Circulation and Medical Imaging, Norwegian University of Science and Technology, Medisinsk Teknisk Forskningssenter, 7491 Trondheim, Norway. eivind.bronstad@ntnu.no
authors.forename: Eivind
authors.initials: E
authors.lastname: Brønstad
authors.forename: Oivind
authors.initials: O
authors.lastname: Rognmo
authors.forename: Arnt Erik
authors.initials: AE
authors.lastname: Tjonna
authors.forename: Hans Henrich
authors.initials: HH
authors.lastname: Dedichen
authors.forename: Idar
authors.initials: I
authors.lastname: Kirkeby-Garstad
authors.forename: Asta K
authors.initials: AK
authors.lastname: Håberg
authors.forename: Charlotte Bjørk
authors.initials: CB
authors.lastname: Ingul
authors.forename: Ulrik
authors.initials: U
authors.lastname: Wisløff
authors.forename: Sigurd
authors.initials: S
authors.lastname: Steinshamn
mesh_terms: D000368:Aged; D005081:Exercise Therapy / Q000379:methods*; D006801:Humans; D007717:Knee; D018482:Muscle, Skeletal / Q000502:physiology*; D029424:Pulmonary Disease, Chronic Obstructive / Q000534:rehabilitation*; D020127:Recovery of Function