Seated Elliptical Exercise, But Not Periodic Standing, Alleviates Sitting-Induced Changes to Arterial Wave Reflections

Abstract

Purpose Sedentary behaviour may contribute to increased central wave reflection due to associated peripheral vasoconstriction, yet its impact on central hemodynamics and the mitigating effects of interventional strategies have not been thoroughly investigated. We tested whether standing, or seated elliptical breaks alleviate the deleterious effects of prolonged sitting on central wave reflections. Methods Eighteen healthy adults (9 females, 25 ± 3 years) completed three 3-hour protocols on separate days: uninterrupted sitting, sitting with periodic standing, and sitting with periodic seated elliptical activity. Central wave reflection, central pulse wave velocity and lower-limb pulse wave velocity were measured before and after each intervention. Results Central relative wave reflection magnitude (RM) increased during sitting (0.31 ± 0.05 to 0.35 ± 0.05; p < 0.01) but did not change following standing (0.30 ± 0.05 to 0.32 ± 0.04; p = 0.19) or elliptical protocols (0.30 ± 0.05 to 0.30 ± 0.04; p > 0.99). The change in RM during prolonged sitting (ΔRM) was attenuated with elliptical activity (0.04 ± 0.05 vs. 0.00 ± 0.03; p = 0.02) but not with periodic standing (0.04 ± 0.04 vs. 0.02 ± 0.05; p = 0.54). In addition, augmentation index and central pulse wave velocity increased following sitting (both p < 0.01) and periodic standing (both p < 0.01) but were unchanged following elliptical activity. Lower limb pulse wave velocity did not change following sitting (p = 0.73) or standing (p = 0.21) but did decrease following elliptical activity (p = 0.03). Conclusions Prolonged sitting without interruptions increased central wave reflection while elliptical but not standing interruptions were able to ameliorate multiple sitting-induced vascular consequences. More work is required to examine the long-term effectiveness of interruption strategies, as well as the optimal type, frequency, and duration for reducing vascular risk associated with sedentary behaviours.