Chronic lung disease (CLD) and any consequent disease-related muscle myopathy along with deconditioning can cause both dyspnea and/or leg discomfort during exertion. These unpleasant experiences frequently lead an individual to reduce or even eliminate daily tasks which adversely impacts quality of life for the individual The primary goal of exercise training is to restore the individual patient to the highest possible level of independent function. Improvements in exertional breathlessness observed following an exercise training program may be due to a physiologic training effect, enhanced mechanical efficiency, and/or psychologic desensitization. Any symptomatic patient with CLD who is motivated to participate should be referred to a pulmonary rehabilitation program, Exercise prescription is based on the principle of "overload" training. Although there is no optimal or best training regimen established for patients with CLD, we provide general guidelines for the mode, frequency, intensity, and duration of exercise training. The recommended minimal intensity of exercise training is 50% of peak work rate, although exercise at "maximal limits tolerated by symptoms" may also be prescribed. The recommended minimal duration of training is 20 to 30 minutes of continuous exertion. Resistance training should be incorporated into a comprehensive exercise program. One approach for patients with CLD to monitor their training intensity is to use a "dyspnea target" as a guide for intensity of training effort.