title: Exercise capacity and quadriceps muscle metabolism following training in subjects with COPD.
abstract: The aim of the study was to determine whether 16 sessions of exercise training, completed twice weekly, alters exercise capacity, quadriceps muscle metabolism, cross-sectional area (CSA) and strength in subjects with chronic obstructive pulmonary disease (COPD). We studied (a) 10 COPD subjects (mean age+/-sem = 71+/-2 years; FEV1 = 0.99+/-0.1 L) before and after 16 sessions of exercise training, and (b) 10 healthy subjects (age = 68+/-3 years). The COPD subjects underwent an incremental peak exercise test using a cycle ergometer and a 6-min walk test: both improved following exercise training (P < 0.05). Magnetic resonance spectroscopy measurements, in quadriceps muscle, of post-exercise phosphocreatinine (PCr) recovery kinetics were used to assess mitochondrial function in vivo: in the COPD subjects pre-training this was 19+/-8% lower than in healthy subjects (P = 0.03), but a 38+/-12% increase was seen in the COPD subjects following training (P = 0.003). Magnetic resonance imaging was used to assess quadriceps CSA: after training in the COPD subjects this showed a 7+/-2% increase (P = 0.03). Quadriceps strength, measured by the best of five maximum voluntary contractions, also showed a 32+/-11% increase in the COPD subjects (P = 0.007). Sixteen sessions of exercise training, performed twice weekly, increased exercise capacity as well as quadriceps mitochondrial capacity, CSA and strength in the subjects with COPD.
authors.affiliation: Department of Respiratory Medicine, Level 11 West, Building 75, Royal Prince Alfred Hospital, Missenden Rd, Camperdown, NSW, Australia 2050. z.mckeough@fhs.usyd.edu.au
authors.forename: Zoe J
authors.initials: ZJ
authors.lastname: McKeough
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Alison
authors.forename: Peter T P
authors.initials: PT
authors.lastname: Bye
authors.forename: Michael I
authors.initials: MI
authors.lastname: Trenell
authors.forename: Toos
authors.initials: T
authors.lastname: Sachinwalla
authors.forename: Campbell H
authors.initials: CH
authors.lastname: Thompson
authors.forename: Graham J
authors.initials: GJ
authors.lastname: Kemp
mesh_terms: D000368:Aged; D015992:Body Mass Index; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test / Q000379:methods; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009119:Muscle Contraction / Q000502:physiology; D053580:Muscle Strength / Q000502:physiology; D029424:Pulmonary Disease, Chronic Obstructive / Q000378:metabolism*; D052097:Quadriceps Muscle / Q000378:metabolism*; D012129:Respiratory Function Tests