Most people feel the difference after about a week of training .
The muscles used in breathing are trainable and a benefit is gained from training them. Studies show that the most effective training is threshold resistance as opposed to a flow depletion method. Both IMP and EMP muscles are trained by breathing in and out with regulated resistance, so it is beneficial to train both. IMP to increase volume and EMP to expel a greater volume of carbon dioxide. When consistently applied one can begin to detect a difference in a few days and experience improved lung function in a few weeks.