title: Improvements in quadriceps force and work efficiency are related to improvements in endurance capacity following pulmonary rehabilitation in COPD patients.
abstract: OBJECTIVE
  The endurance time has been reported to be the most sensitive measure of improved exercise capacity in response to a variety of interventions for COPD. The aim of the present study was to determine whether the improvements in quadriceps force and measures obtained from a symptom-limited maximal test contributed to the improvements in endurance time following pulmonary rehabilitation.
  
  
  METHODS
  Fifty-seven consecutive COPD subjects completed a 10-week pulmonary rehabilitation program. The subjects completed a symptom-limited incremental cycle ergometry test and a constant work rate test before and after pulmonary rehabilitation. Peripheral and respiratory muscle strength was also measured. The relationships between the change in endurance time and the changes obtained from the incremental test and muscle strength test were investigated.
  
  
  RESULTS
  The endurance time showed the greatest improvement among the exercise capacity indices. The changes in endurance time were significantly correlated to changes in quadriceps force, peak work rate, anaerobic threshold and work efficiency on the incremental load test. In the multiple stepwise regression analysis, changes in quadriceps force and work efficiency measured on the maximal exercise test were selected.
  
  
  CONCLUSIONS
  These findings suggest that the improvements in endurance time after pulmonary rehabilitation may be explained by increased quadriceps force and improvements in peak work rate and work efficiency.
authors: Department of Rehabilitation, Tosei General Hospital, Japan.
authors: Shinichi
authors: S
authors: Arizono
authors: Hiroyuki
authors: H
authors: Taniguchi
authors: Osamu
authors: O
authors: Nishiyama
authors: Yasuhiro
authors: Y
authors: Kondoh
authors: Tomoki
authors: T
authors: Kimura
authors: Kensuke
authors: K
authors: Kataoka
authors: Tomoya
authors: T
authors: Ogawa
authors: Fumiko
authors: F
authors: Watanabe
authors: Koichi
authors: K
authors: Nishimura
authors: Hideaki
authors: H
authors: Senjyu
authors: Kazuyuki
authors: K
authors: Tabira
mesh_terms: D000368:Aged; D005080:Exercise Test / Q000379:methods; D005081:Exercise Therapy / Q000379:methods*; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength / Q000502:physiology*; D010807:Physical Endurance / Q000502:physiology*; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis / Q000503:physiopathology* / Q000534:rehabilitation*; D052097:Quadriceps Muscle / Q000502:physiology*