Exercise training has been shown to reduce breathlessness and improve the exercise tolerance of people with lung disease. However, the effect of exercise training on the walking speed selected by these people during day-to-day life is unknown. Furthermore,the investigator do not know if exercise training changes the maximum speed that these people can walk at for a long period of time. This study will examine the relationship between walking speed and walking endurance before and following exercise training in people with lung disease and contribute importantly to our understanding of how patients choose to walk in relation to their capabilities.