The crural diaphragm (CD) is an essential component of the esophagogastric junction (EGJ) and inspiratory exercises may modify its function. This study's goal is to verify if inspiratory muscle training (IMT) improves EGJ motility and gastroesophageal reflux (GER). Twelve GERD (7 males, 20-47 years, 9 esophagitis, 3 NERD) and 7 healthy volunteers (3 males, 20-41 years) performed esophageal pH monitoring, manometry, and heart rate variability (HRV) studies. A 6-cm-sleeve catheter measured average EGJ pressure during resting, peak inspiratory EGJ pressures during sinus arrhythmia maneuver (SAM) and inhalations under 17-cmH2O, 35-cmH2O, and 70-cmH2O loads (TH maneuvers), and along 1 hour after a meal. GERD patients entered a 5-days-a-week IMT program. One author scored heartburn and regurgitation before and after IMT. IMT increased average EGJ pressure (19.7 ± 2.4 mmHg v 29.5 ± 2.1 mmHg, p < 0.001), inspiratory EGJ pressure during SAM (89.6 ± 7.6 mmHg v 125.6 ± 13.3 mmHg, p = 0.001), and during TH maneuvers. The EGJ-pressure gain across 35 cmH2O and 70 cmH2O loads was lower for GERD volunteers. The number and cumulative duration of the tLESR decreased after IMT. Proximal progression of GER decreased after IMT but not the distal acid exposure. LF power increased after IMT and the higher its increment the lower the increment of supine acid exposure. IMT decreased heartburn and regurgitation scores. In conclusion, IMT improved EGJ pressure, reduced GER proximal progression, and GERD symptoms. Some GERD patients have a CD failure and IMT may prove beneficial as a GERD add-on treatment.