Acute effects of breaking up prolonged sitting on fatigue and cognition: a pilot study

Abstract

ObjectivesTo compare the acute effects of uninterrupted sitting with sitting interrupted by brief bouts of light-intensity walking on self-reported fatigue, cognition, neuroendocrine biomarkers and cardiometabolic risk markers in overweight/obese adults.DesignRandomised two-condition crossover trial.SettingLaboratory study conducted in Melbourne, Australia.Participants19 overweight/obese adults (45–75 years).InterventionsAfter an initial 2 h period seated, participants consumed a meal-replacement beverage and completed (on 2 days separated by a 6-day washout period) each condition over the next 5 h: uninterrupted sitting (sedentary condition) or sitting with 3 min bouts of light-intensity walking every 30 min (active condition).Primary outcome measuresSelf-reported fatigue, executive function and episodic memory at 0 h, 4 h and 7 h.Secondary outcome measuresNeuroendocrine biomarkers and cardiometabolic risk markers (blood collections at 0 h, 4 h and 7 h, blood pressure and heart rate measured hourly and interstitial glucose measured using a continuous glucose monitoring system).ResultsDuring the active condition, fatigue levels were lower at 4 h (−13.32 (95% CI −23.48 to −3.16)) and at 7 h (−10.73 (95% CI −20.89 to −0.58)) compared to the sedentary condition. Heart rate was higher at 4 h (4.47 (95% CI 8.37 to 0.58)) and at 7 h (4.32 (95% CI 8.21 to 0.42)) during the active condition compared to the sedentary condition. There were no significant differences between conditions by time for other variables. In the sedentary condition, changes in fatigue scores over time correlated with a decrease in heart rate and plasma dihydroxyphenylalanine (DOPA) and an increase in plasma dihydroxyphenylglycol (DHPG).ConclusionsInterrupting prolonged sitting with light-intensity walking breaks may be an effective fatigue countermeasure acutely. Fatigue levels corresponded with the heart rate and neuroendocrine biomarker changes in uninterrupted sitting in this pilot study. Further research is needed to identify potential implications, particularly for the occupational health context.Trial registration numberACTRN12613000137796; Results.

Effects of Interrupting Prolonged Sitting with Physical Activity Breaks on Blood Glucose, Insulin and Triacylglycerol Measures: A Systematic Review and Meta-analysis

“…Physical activity (PA) breaks in sitting were also more effective than one continuous bout of exercise on glucose. Nonetheless because this review only included five studies on glucose, published between 2011 and 2014, some relevant earlier studies [7][8][9][10][11][12] and more recent studies [13][14][15][16][17][18][19][20][21][22] might have been omitted or missed. There was no date restriction in Benatti et al [23] but no meta-analysis was performed.…”

“…"Physically active" was defined as either exceeding the recommended 150 min of moderate to vigorous physical activity (MVPA) per week, or reported as "recreationally active" [7,8,45]. "Sedentary" was defined as not working in a non-sedentary job [46], exceeding 5 h of sitting time per day [15,22,47], or any study that defined participants as sedentary. If a study did not report the PA, body mass or health status of participants, it was omitted from the subgroup analysis.…”

“…Other than a few studies [15,17,21,46,47] most did not utilise or report any form of blinding. All studies included in the meta-analysis, except one [77], were randomised, but only a few reported the randomisation methods clearly [17,19,21,22,46,47,62]. Additionally, with the exception of a few studies [15,17,19,46,47,62], most did not report how any possible missing data were handled.…”

“…Furthermore, blood was drawn, for example, just before PA breaks [46,47] or in rested, sedentary conditions, 1 day after PA breaks [7,8], every 10 min [16], once every 2 h [10,20] or assessed via CGMS [12,14,15,22,71,82,83]. Thus, results could have been affected by differing blood draw protocols [99,147].…”

Effects of acute prolonged sitting on cerebral perfusion and executive function in young adults: A randomized cross‐over trial

“…While the term executive function is broad, it generally refers to the hypothesized processes that control other brain processes that are critical to everyday functioning (Hughes, 2013). The limited available literature does indicate that prolonged sitting decreases cerebral blood flow by 5% (Carter et al, 2018), cerebral vascular conductance by 6% (Carter et al, 2018), increases perceived fatigue by 25% (Wennberg et al, 2016), and increases problem solving errors by 56% (Baker, Coenen, Howie, Williamson, & Straker, 2018). Conversely, regular walking breaks prevent the decline in cerebral blood flow associated with prolonged sitting (Carter et al, 2018).…”