PROLONGED STANDING INCREASES LOWER PERIPHERAL ARTERIAL STIFFNESS INDEPENDENT OF WALKING BREAKS

Authors

AR Caldwell
BT Harris
ME Rosa-Caldwell
M Payne
B Daniels
KM Gallagher
MS Ganio, FACSM

Abstract

Aaron R. Caldwell^Ɨ1, Benjamin T. Harris*¹, Megan E. Rosa-Caldwell^Ɨ1, Marcus Payne^Ɨ1, Bryce Daniels^Ɨ1, Kaitlin M. Gallagher^ǂ1, Matthew S. Ganio^ǂ1, FACSM. ¹University of Arkansas, Fayetteville, AR.

Prolonged sitting creates an atherogenic environment that causes reductions in arterial function. Standing desks have been promoted as a healthy alternative to sitting, but the cardiovascular benefits of standing desks have not been thoroughly investigated. Physical activity, such as taking walking breaks, increases shear stress, and thereby prevents sitting-induced reductions in arterial function. Therefore, walking breaks, even when compared to standing may provide cardiovascular benefits. Purpose: First, to observe changes in arterial stiffness, as assessed by pulse wave velocity (PWV), with a 2 hour bout of standing. Second, to determine if short, intermittent walking bouts provide a comparative advantage to standing alone. Methods: 20 apparently healthy adults (BMI = 22.9 ± 3.2 kg/m²; Age = 21 ± 5 years old) stood for 2 consecutive hours while being assessed for heart rate (HR), mean arterial pressure (MAP), and central (C_PWV), upper peripheral (U_PWV), and lower peripheral (L_PWV) PWV before, during, and after the standing bout. Subjects participated in two trials in a randomized order. In one trial, the subjects stood at a standing desk immobile for 2 hours. In the other trial, subjects performed 5-minute walking breaks after every 25 minutes of standing for a total of two hours of standing with 4 walking breaks. A repeated measures ANOVA utilized for statistical analyses. Results: There was no time by trial interaction for any measure of arterial stiffness (p = 0.82, p = 0.21, and p = 0.15; for C_PWV, U_PWV, and L_PWV respectively). However, from beginning to end of each trial L_PWV increased 85 ± 126 cm/s independent of trial (i.e., main effect of time; p < 0.001). There was a non-significant tendency for greater increases in L_PWV during the standing (120 ± 142 cm/s) versus the walking trial (50 ± 127 cm/s; p = 0.15). There were no differences regarding HR or MAP (p > 0.05) CONCLUSION: Standing for 2 hours leads to increases in peripheral arterial stiffness. Walking breaks during 2 hours of standing did not significantly attenuate these changes. However, the suggestive evidence (p=0.15) for walking breaks to improve L_PWV suggests that future studies should investigate longer duration trials and/or longer walking breaks that are applicable to occupational settings, such as assembly-line work.

Supported by funding from Southwest Center for Occupational and Environmental Health NIOSH Pilot Project Research Training Program

Recommended Citation

Caldwell, AR; Harris, BT; Rosa-Caldwell, ME; Payne, M; Daniels, B; Gallagher, KM; and Ganio, FACSM, MS (2017) "PROLONGED STANDING INCREASES LOWER PERIPHERAL ARTERIAL STIFFNESS INDEPENDENT OF WALKING BREAKS," International Journal of Exercise Science: Conference Proceedings: Vol. 11: Iss. 5, Article 33.
Available at: https://digitalcommons.wku.edu/ijesab/vol11/iss5/33