[Purpose] The purpose of this study was to clarify changes in superficial femoral artery blood flow during upper limb cranking exercise. [Methods] Cranking exercise was performed using both upper limbs by 12 healthy adults (age, 20.8 ± 0.4 years). Cardiopulmonary exercise test was performed to determine anaerobic threshold (AT) in advance. After 4 minutes of pre-exercise rest, steady load exercise was performed at the intensity of AT for 9 minutes, followed by 4 minutes of rest after the exercise. Superficial femoral artery blood flow and shear rate were calculated from the blood flow velocity and vessel diameter obtained by using a Doppler imaging system. The heart rate (HR) and cardiac output (CO) were non-invasively measured at rest and during exercise. [Results] Superficial femoral artery blood flow was significantly higher from 6 minutes after the beginning of exercise compared to that obtained at pre-exercise rest (147±8 vs. 226±21 mL/min, 1-min of rest vs. 6-min of exercise, p<0.05). The shear rate was significantly higher from 5 minutes after the beginning of exercise (14±1 vs. 19±1 s\sl185\slmult0 -1, 1-min of rest vs. 5-min of exercise, p<0.05). The HR and CO were significantly higher from 1 minute after the beginning of exercise (HR: 75±2 vs. 98±2 bpm, CO: 5.3±0.3 vs. 7.2±0.4 L/min, 1-min of rest vs. 1-min of exercise, p<0.05, respectively). [Conclusion] In healthy male adults, superficial femoral artery blood flow increased during middle intensity of arm cranking exercise as compared to that obtained at rest. The increase in blood flow was observed after 6 minutes of the beginning of exercise.
