In October 2018 researchers from Canada published the results of their study to assess whether cannabis could reduce breathlessness during exercise and improve exercise endurance time in individuals with chronic obstructive pulmonary disease. 16 individuals with advance chronic obstructive pulmonary disease were given 35 mg of inhaled vaporized cannabis and then undertook a cardiopulmonary cycle endurance exercise. On a separate occasion 35 mg of a placebo control cannabis was taken and the cardiopulmonary exercise repeated. On each occasion spirometry, cognitive function, psychoactivity, and mood were assessed. Results showed that cannabis had no effect on breathlessness during exercise, exercise endurance time, breathing pattern, spirometry, cognitive function, psychoactivity, and mood when compared to the placebo control cannabis.
Abdallah SJ et al. Effect of Vaporized Cannabis on Exertional Breathlessness and Exercise Endurance in Advanced Chronic Obstructive Pulmonary Disease. A Randomized Controlled Trial. Ann Am Thorac Soc. 2018 Oct;15(10):1146-1158