Dear Editor-in-Chief

Arterial stiffness is one of the most important de-terminants of increased systolic arterial pressure and pulse pressure, and is closely associated with hypertension, hyperlipidemia, type 2 diabetes melli-tus, and artery hardening (1-2). The American Col-lege Sports Medicine guideline states regular exer-cise can prevent and treat cardiovascular system dysfunction including arterial stiffness (3). Howev-er, the meta-analysis of Williams (2001) shows physical fitness level owing to regular exercise and levels of daily physical activity (PA) are indepen-dent cardiovascular risk factors (4). As PA has also been reported to protect the cardiovascular system via increased physical fitness level, additional stu-dies are required to clarify the associations betwee