Background: The current understanding of ventilator efficiency variables during ramp exercise testing in the normal Japanese population is insufficient, and the responses of tidal volume (VT) and minute ventilation (VE) to the ramp exercise test in the normal Japanese population are not known. Methods: A total of 529 healthy Japanese subjects aged 20-78 years underwent cardiopulmonary exercise testing using a cycle ergometer with ramp protocols. VT and VE at rest, at anaerobic threshold, and at peak exercise were determined. The slope of VE versus carbon dioxide (VCO 2 ) (VE vs. VCO 2 slope), minimum VE/VCO 2 , and oxygen uptake efficiency slope (OUES) were determined. Results: For males and females in their 20 s, peak VT (VTpeak) was 2192 AE 376 and 1509 AE 260 mL (p < 0.001), peak VE (VEpeak) was 80.6 AE 18.7 and 57.7 AE 13.9 L/min (sex differences p < 0.001), the VE vs. VCO 2 slope was 24.4 AE 3.2 and 25.7 AE 3.2 (p = 0.035), the minimum VE/VCO 2 was 24.2 AE 2.3 and 27.0 AE 2.8 (p < 0.001), and the OUES was 2452 AE 519 and 1991 AE 315 (p < 0.001), respectively. VTpeak and VEpeak decreased with age and increased with weight and height. The VE vs. VCO 2 slope and minimum VE/VCO 2 increased with age, while conversely, the OUES decreased with age. Conclusions: We have established the normal range of VT and VE responses, the VE vs. VCO 2 slope, the minimum VE/VCO 2 , and the OUES for a healthy Japanese population. Some of these parameters were influenced by weight, height, sex, and age. These results provide useful reference values for interpreting the results of cardiopulmonary exercise testing in cardiac patients.