Six-minute walking versus shuttle walking: responsiveness to bronchodilation in chronic obstructive pulmonary disease.

Background: The responsiveness of the endurance shuttle walk to functional changes following bronchodilation has recently been reported. The current literature suggests that the 6 min walking test (6MWT) is less responsive to bronchodilation than the endurance shuttle walk.

Aim: To compare bronchodilator-induced changes in exercise performance with the 6MWT and the endurance shuttle walk.

Lipofuscin accumulation in the vastus lateralis muscle in patients with chronic obstructive pulmonary disease.

Exercise-induced oxidative stress has been reported in patients with chronic obstructive pulmonary disease (COPD) and may play a role in muscle fatigue. It is speculated that oxidative stress during exercise originates from the contracting muscles but this has not been documented. The accumulation of lipofuscin, a marker of cellular oxidative damage, was evaluated in the vastus lateralis muscle in 17 patients with COPD and 10 healthy subjects of similar age.