Upper limb exercises using varied workloads and their association with dynamic hyperinflation in patients with COPD.

BACKGROUND

Increased ventilation during upper limb exercises (ULE) in patients with COPD is associated with dynamic hyperinflation (DH) and a decrease in inspiratory capacity (IC). The best level of ULE load training is still unknown. Our objective was to evaluate the dynamic hyperinflation development during ULE using three constant workloads.

METHODS

This was a prospective, randomized protocol involving 24 patients with severe COPD (FEV(1) < 50%) performing an endurance symptom-limited arm exercise of up to 20 min in an arm cycloergometer with different workloads (50%, 65%, and 80% of the maximal load). Ventilation, metabolic, and lung function variables (static IC pre-exercise and postexercise) were measured.

RESULTS

DH was observed during exercises with 65% (-0.23 L) and 80% (-0.29 L) workloads (P < .0001). Total time of exercise with 80% workload (7.6 min) was shorter than with 50% (12.5 min) (P < .0005) and with 65% (10.1 min; not significant). Oxygen consumption percent predicted (VO(2)) (P < .01) was lower with 50% workload than with 80%. Eighty percent workload showed lower work efficiency (VO(2) [mL/kg]/exercise time) than the other two workloads (P < .0001).

CONCLUSION

Different workloads during upper limb exercises showed a direct influence over dynamic hyperinflation and the endurance exercise duration.