We report a case in which a favorable course was obtained by using KAATSU training® and BCAA intake early after aortic valve replacement surgery. The patient was a 43-year-old male with low cardiac function who underwent aortic valve replacement surgery. Heart failure and hypotension persisted while waiting for surgery. He tended to line on a bed all day, so that disuse muscular atrophy advanced. Therefore, in addition to the postoperative rehabilitation program, KAATSU training and BCAA intake were performed postoperatively and continued in outpatient rehabilitation. The KAATSU training was performed using knee extension twice or three times a week. For BCAA intake (2.5 g), one pack of jelly containing BCAA (Reha-Time Jelly, Clinico Co., Ltd.) was taken within 30 minutes after the training. About 3 months later, the thigh circumference (+ 7.3 cm), the maximum voluntary isometric contraction of knee extension (+ 20 kgf), the quadriceps muscle thickness (+ 1 cm) evaluated by a B-mode ultrasound, the muscle mass of the lower limb (+ 1 kg), and a marked increase in thigh muscle cross-sectional area as measured by CT scan were observed. No deterioration of circulatory hemodynamics and side effects were observed during the course. In conclusion, the combined use of KAATSU training and BCAA intake early after cardiac operation seems to be a safe and effective way to obtain muscle hypertrophy and muscle strengthening, but further studies are needed to clarify it.