Author(s): NISHIWAKI, M., KUME, D., KIKUCHI, K., Institution: OSAKA INSTITUTE OF TECHNOLOGY, Country: JAPAN, Abstract-ID: 2033

INTRODUCTION:
Many previous studies have demonstrated that acute or regular exercises reduce Pulse Wave Velocity (PWV) as an index of arterial stiffness. The increased arterial stiffness is an independent risk factor for future cardiovascular diseases or mortalities, so preventing arterial stiffness by exercise is of paramount importance, regardless of age. In recent, one-legged physical exercise (aerobic, resistance, and stretching) has been shown to acutely reduce arterial stiffness in the exercised limb, but not in the none-exercised limb. These findings thus raise the possibility that arterial stiffness responses and adaptations to exercise are mainly involved in physical exercise-induced local factors as exercise stimuli. However, the influences of acute exercise types on segmental arterial stiffness are now well unknown. Therefore, this study aimed to examine the effects of acute aerobic exercise for upper or lower limbs on segmental arterial stiffness.
METHODS:
Twelve young adults (22 ± 1 years) participated in three separate trials of 40 min in random order and on different days: (1) resting and sitting on a comfortable chair, as a control (CON); (2) aerobic mock gardening activity exercise for upper limbs (UE); (3) aerobic cycling exercise for lower limbs (LE). Both exercises were performed at the same heart rate levels (target heart rate: 117 ± 17 beats/min), as determined beforehand by a pretest for each participant. Before (Pre) and after (Post) the exercises, heart-brachial PWV (hbPWV), which reflects arterial stiffness of the upper limbs from the aorta to the brachium; brachial-ankle PWV (baPWV), which reflects arterial stiffness of central (large arteries in the cardiothoracic region) and leg from the femoral to the ankle; and heart-ankle PWV (haPWV), which reflects systemic arterial stiffness, were measured as an index of segmental arterial stiffness.
RESULTS:
No significant differences in baseline parameters were observed among trials. After the exercise, hbPWV significantly reduced in both UE (-11.4 ± 9.7%) and LE (-6.6 ± 8.1%) trials, but did not in CON (5.1 ± 6.0%) trials. On the other hand, interestingly, baPWV was significantly reduced only in the LE (-2.9 ± 5.2%) trials. In addition, baPWV in UE (3.1 ± 5.6%) trials significantly increased after exercise regardless of no significant changes in CON (1.8 ± 4.6%) trials. Finally, haPWV significantly reduced in both UE (-5.0 ± 5.7%) and LE (-4.7 ± 6.1%) trials, but did not in CON (3.4 ± 3.6%) trials.
CONCLUSION:
Therefore, our data indicate that cycling exercise for lower limbs induces reductions in relatively systemic arterial stiffness (i.e., exercise-related direct and indirect regions). However, the influences of upper limb exercise on arterial stiffness are relatively limited and have a strong locality.