LAUSR

PURPOSE Acute or regular stretching exercises reduce arterial stiffness, but whether stretching exercises per se can reduce central arterial stiffness remain controversial. Recent studies have suggested that mechanical stimulation of arteries can directly modulate arterial stiffness, rather than causing systemic effects. Thus, this study aimed to examine the effects of trunk stretching using an exercise ball on central arterial stiffness and carotid arterial compliance. METHODS Twelve healthy young adults participated in two different trials for 30 min each in random order on separate days: a resting and sitting trial (CON); and supervised passive trunk stretching using the exercise ball (EB). In EB, subjects preformed six types of passive trunk stretching using the exercise ball. At each site, passive stretching was held for 30 s followed by a 30-s relaxation period, repeated 5 times during the 30-min trial. In CON, subjects rested on a comfortable chair for 30 min. RESULTS After the experiment, carotid-femoral pulse wave velocity was significantly reduced in EB, but not in CON (EB vs. CON: -4.5 ± 1.2% vs. 0.2 ± 0.9%; P < 0.05). Carotid arterial compliance was also significantly increased in EB, but not in CON (EB vs. CON: 38.4 ± 11.4% vs. 4.1 ± 9.4%; P < 0.05). Supplemental experiments also confirmed that stretching of lower extremity did not reduce carotid-femoral pulse wave velocity. CONCLUSION Our findings indicate that acute, direct trunk stretching using an exercise ball reduces central arterial stiffness and increases carotid arterial compliance in young healthy men.