Ventilatory requirements of quadriceps resistance training in people with COPD and healthy controls.

Abstract

BackgroundIt is proposed that resistance training (RT) does not activate the cardiopulmonary system to the same extent as whole-body exercise. This is important for patients with chronic obstructive pulmonary disease (COPD) who are ventilatory limited.ObjectiveThe aim was to assess the ventilatory response to an isokinetic quadriceps RT program in people with COPD and healthy controls.DesignObservational.Registration numberISRCTN22764439.SettingOutpatient, university teaching hospital.Participants and outcome measuresPeople with COPD (n=14) and healthy controls (n=11) underwent breath-by-breath analysis of their ventilation during an RT session (five sets of 30 maximal knee extensions at 180°/sec). Subjects performed a maximal cycle ergometry test (CET) at baseline. Peak ventilation (VE; L/min) and oxygen consumption (VO2; mL/kg/min) were collected. The same system measured VO2 and VE during the RT session. Parameters are presented as a percentage of the maximal CET. Isokinetic workload, symptom scores, heart rate (HR), and oxygen saturation were documented post-training.ResultsPeople with COPD worked at higher percentages of their maximal capacity than controls (mean range between sets 1–5 for VO2 =49.1%–60.1% [COPD], 45.7%–51.43% [controls] and for VE =57.6%–72.2% [COPD], 49.8%–63.6% [controls]), although this was not statistically significant (P>0.1 in all cases). In absolute terms, the difference between groups was only significant for actual VO2 on set 2 (P<0.05). Controls performed more isokinetic work than patients with COPD (P<0.05). Median Borg symptom scores after RT were the same in both groups (3 breathlessness, 13 exertion), no de-saturation occurred, and both groups were training at ≥65% of their maximum HR.ConclusionNo statistically significant differences were found between people with COPD and healthy controls for VO2 and VE achieved during training. The symptoms associated with training were within acceptable limits.