Pedometer‐determined physical activities of daily living can affect blood pressure regulation in healthy young adults after postural change

Abstract

BackgroundNumerous studies have examined the effects of physical activity (PA) on blood pressure (BP) or autonomic function through exercise interventions. However, few studies have used non‐intervention methods to observe the association between pedometer‐determined physical activities of daily living and BP and autonomic function in healthy young adults.ObjectiveThe purpose of this study was to examine whether the differences in pedometer‐determined physical activities of daily living cause the variation in BP and autonomic nerve activity in healthy young adults.MethodsFourteen Japanese healthy young adults aged 20–24 years participated in this study. A pedometer was used to measure the step count and to calculate other indexes of physical activity for 1 week. It was determined that 5 individuals comprised the high PA group (≥23 METs ■ hr/wk) and 9 individuals comprised the low PA group (<23 METs ■ hr/wk). Weight, height, BMI, muscle mass, body fat percentage, and basal metabolic rates were measured using a body composition analyzer. Then, we measured BP and heart rate variability at rest and during the postural change from the supine position to the sitting position. The ratio of low frequency (LF) components (0.04–0.15 Hz) to high frequency (HF) components (0.15–0.40 Hz) was used as an index of sympathetic nerve activity. HF was used as an index of parasympathetic nerve activity.ResultsThe high PA group exhibited significantly higher calorie consumption (P < 0.01) and fat combustion (P < 0.01). The mean diastolic blood pressure value in the sitting position (P < 0.02) for the high PA group was significantly higher than that of the low PA group. After a postural change from the supine position to the sitting position, although there were no significant changes in LF/HF and HF in both groups, systolic blood pressure (SBP) in the high PA group increased significantly (P < 0.05); however, the low PA group had a significant subsequent decrease in SBP after changing from the supine position to the sitting position (P < 0.01).ConclusionsThrough the measurement of pedometer‐determined physical activities of daily living in healthy adults, we concluded that individuals who performed more pedometer‐determined physical activities of daily living can maintain normal responses in blood pressure after a postural change, compared to individuals who performed fewer pedometer‐determined physical activities of daily living.Support or Funding InformationThis work was supported, in part, by a Grant‐in‐aid for Scientific Research (B) (25305018) from the Japan Society for the Promotion of Science.