Bilevel exercise training and directed breathing relieves exertional dyspnea for male smokers.

Objective: The purpose of this study was to compare the effects on exertional dyspnea and exercise capacity of square wave (bilevel) cycle ergometry endurance exercise training (SWEET) and comprehensive directed breathing vs. walking while pushing an OxCar and traditional diaphragmatic breathing for male smokers with normal spirometry but reduced exercise capacity.

Design: This was a prospective randomized trial of 24 unmedicated men with exertional dyspnea assigned to SWEET or OxCar groups.