Leg-fidgeting versus standing breaks during prolonged sitting: Impacts on blood pressure and heart rate in young women.

The objective of this work was to examine whether leg-fidgeting breaks during prolonged sitting could be a practical alternative to standing breaks in preventing blood pressure (BP) and heart rate (HR) impairments. Young women (n = 16; age = 21.9 ± 3.0 years; body mass index = 21.1 ± 4.9 kg/m²) completed three 3-h prolonged sitting conditions in a random order, including: (1) uninterrupted prolonged sitting, (2) interrupted prolonged sitting every 20 min with standing for 5 min, and (3) interrupted prolonged sitting every 4 min with leg-fidgeting for 1 min. Oscillometric brachial BP and HR were measured at baseline and after 1, 2 and 3 h of prolonged sitting. Generalized linear mixed models with random effects evaluated the effects of the three prolonged sitting conditions on BP and HR while controlling for baseline values. Effect sizes were estimated using Cohen's d. No significant differences were observed between the three prolonged sitting conditions for all BP variables (P > 0.05 for all). HR was significantly lower when prolonged sitting was interrupted with standing (β = -4.406 beats; d = 0.46; P = 0.009) or leg-fidgeting (β = -3.802 beats; d = 0.46; P = 0.023) compared to the uninterrupted prolonged sitting condition. These findings suggest that leg-fidgeting breaks during prolonged sitting may serve as a practical alternative to standing breaks in preventing some prolonged sitting-induced cardiovascular impairments, particularly HR, in young women.