“This study investigated the relationship between the intensity of an inspiratory muscle training programme and its effect on respiratory muscle strength, exercising heart rate, and ratings of perceived exertion.”
Six weeks of both MAX (subjects that trained at 100% of maximum inspiratory pressure i.e. MIP) and SUB (subjects that trained at 80% MIP) training were sufficient to improve inspiratory muscle strength. However, exercising heart rate and perceived exertion decreased with MAX training only.
Read The effects of different inspiratory muscle training intensities on exercising heart rate and perceived exertion >