May 1, 1997American Journal of Respiratory and Critical Care Medicine445 citations
View Full PaperPhysiologic Benefits of Exercise Training in Rehabilitation of Patients With Severe Chronic Obstructive Pulmonary Disease
Key Result
Rigorous rehabilitative exercise training in patients with severe COPD increased peak work rate by 36% (p<0.001) and constant work rate duration by 77% (p<0.001).
Structured PICO
Does rigorous rehabilitative exercise training improve exercise tolerance and physiological responses in patients with severe COPD?
P
Population
25 patients with severe COPD (mean age 68 years) who underwent a 6-week rigorous rehabilitative exercise training program.
I
Intervention
Rehabilitation program including three 45-minute sessions per week of cycle ergometer training for 6 weeks at near maximal targets.
O
Outcome
Exercise tolerance (peak work rate in incremental test and duration of constant work rate test) and physiological exercise responses.surrogate
Rigorous exercise training in severe COPD improves exercise tolerance and yields a more efficient breathing pattern.
Main Result
Effect estimate: 36% increase in peak work rate; 77% increase in CWR duration
p-value: p=<0.001
Abstract
We determined the effect on exercise tolerance and physiological exercise responses of rigorous rehabilitative exercise training in chronic obstructive pulmonary disease (COPD). Fifteen men and 10 women (mean age, 68 +/- 6 yr; FEV1, 0.93 +/- 0.27 L) participated in a rehabilitation program with an exercise component of three per week 45-min sessions of cycle ergometer training for 6 wk with exercise intensity kept near maximal targets. Before and after rehabilitation, patients performed an incremental test and a constant work rate (CWR) test at 80% of the peak work rate in the preprogram incremental test. Ventilation (V(E)) and gas exchange were measured breath by breath; arterialized venous blood was analyzed for blood gas determinations and lactate. Rehabilitation yielded an average increase in peak work rate in the incremental test of 36% (p < 0.001), and in the duration of the CWR test of 77% (p < 0.001). In the CWR test, the kinetics of O2 uptake, CO2 output, V(E), and heart rate were markedly slower than those of healthy subjects. After training, mean response time decrease averaged 17, 22, 34, and 29%, respectively (p < 0.02), evidence of a physiologic training effect. Further, for identical CWR tasks, V(E) was 10% lower (p < 0.02) after training, attributable to altered breathing pattern: tidal volume increased by 8% and respiratory rate decreased by 19%, yielding lower V(D) /V(T) (0.46 versus 0.53 p < 0.005). Rigorous exercise training for patients with severe COPD yields more efficient exercise breathing pattern and lower V(E); this is associated with improved exercise tolerance.