Respiratory muscle training extends exercise tolerance without concomitant change to peak oxygen uptake: Physiological, performance and perceptual responses derived from the same incremental exercise test

Background and objective There is conjecture over the efficacy of respiratory muscle training ( RMT ). The aim of this study was to establish whether or not exercise tolerance, physical performance and effort perceptions are influenced by RMT .Methods Thirty‐six healthy males (age 24 ± 4) agreed to participate (experimental group ( EXP ) n  = 18, control ( CON ) n  = 18). RMT was performed using an inspiratory pressure‐threshold training device at either 55% ( EXP ) or 10% ( CON ) of maximal inspiratory effort. Measurements of spirometry and maximal static inspiratory mouth pressure were taken before and after 4 weeks of RMT in addition to an incremental test to volitional exhaustion for the determination of: (i)V ˙O 2p ⁢ e a k ; (ii) maximal velocity at volitional exhaustion ( v V ˙O 2p ⁢ e a k )); (iii) time to volitional exhaustion; and (iv) effort perceptions. Results There were no differences in spirometry, but mean maximal static inspiratory mouth pressure increased significantly in EXP ( P  < 0.01).V ˙O 2p ⁢ e a kwas unchanged following the 4‐week intervention for both EXP and CON , although the proportion of EXP attaining the criteria for aV ˙O 2plateau significantly increased ( P  < 0.05). Both time to volitional exhaustion ( P  < 0.05) and v V ˙O 2p ⁢ e a kwere significantly improved for EXP ( P  < 0.05), while effort perceptions were reduced ( P  < 0.05). Conclusions EXP tolerated higher running velocities during incremental exercise and demonstrated a significant flattening (plateau) ofV ˙O 2after training. This suggests that RMT may promote an improved performance outcome v V ˙O 2p ⁢ e a kprobably as a result of blunted afferent sensations reducing the perceived discomfort of exercise at high ventilatory loads.