We investigated central fatigue during maximal exercise (EXmax) after 12×20-min respiratory muscle endurance training (eRMT) sessions over 4 weeks using cerebral near-infrared spectroscopy (NIRS; left, right prefrontal cortices: LPFC, RPFC); and self-reported effort perceptions (RPE). Healthy participants improved eRMT performance with no spirometry changes. Pre-eRMT, EXmax oxygenated (O2Hb), deoxygenated (HHb), and total (tHb) hemoglobin increases were larger in LPFC than RPFC. Post-eRMT, EXmax O2Hb, HHb, and tHb increases were smaller in LPFC than RPFC. Post-eRMT EXmax RPE were smaller. eRMT-induced LPFC-to-RPFC hemodynamic shifts during EXmax may facilitate decreased RPE.