title: Acute effects of breaking up prolonged sitting on fatigue and cognition: a pilot study.
abstract: OBJECTIVE
  To 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.
  
  
  METHODS
  Randomised two-condition crossover trial.
  
  
  METHODS
  Laboratory study conducted in Melbourne, Australia.
  
  
  METHODS
  19 overweight/obese adults (45-75 years).
  
  
  METHODS
  After 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).
  
  
  METHODS
  Self-reported fatigue, executive function and episodic memory at 0 h, 4 h and 7 h.
  
  
  METHODS
  Neuroendocrine 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).
  
  
  RESULTS
  During 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).
  
  
  CONCLUSIONS
  Interrupting 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.
  
  
  BACKGROUND
  ACTRN12613000137796; Results.
authors.affiliation: Department of Public Health and Clinical Medicine, Umeå University, Umeå, Sweden.
authors.forename: Patrik
authors.initials: P
authors.lastname: Wennberg
authors.affiliation: CEDAR, Center for Demographic and Aging Research, Umeå University, Umeå, Sweden.
authors.forename: Carl-Johan
authors.initials: CJ
authors.lastname: Boraxbekk
authors.affiliation: Baker IDI Heart and Diabetes Institute, Melbourne, Australia School of Sport Science, Exercise & Health, University of Western Australia, Perth, Australia.
authors.forename: Michael
authors.initials: M
authors.lastname: Wheeler
authors.affiliation: Baker IDI Heart and Diabetes Institute, Melbourne, Australia Central Clinical School, Monash University, Melbourne, Australia.
authors.forename: Bethany
authors.initials: B
authors.lastname: Howard
authors.affiliation: Baker IDI Heart and Diabetes Institute, Melbourne, Australia Central Clinical School, Monash University, Melbourne, Australia.
authors.forename: Paddy C
authors.initials: PC
authors.lastname: Dempsey
authors.affiliation: Baker IDI Heart and Diabetes Institute, Melbourne, Australia Central Clinical School, Monash University, Melbourne, Australia.
authors.forename: Gavin
authors.initials: G
authors.lastname: Lambert
authors.affiliation: Baker IDI Heart and Diabetes Institute, Melbourne, Australia.
authors.forename: Nina
authors.initials: N
authors.lastname: Eikelis
authors.affiliation: Baker IDI Heart and Diabetes Institute, Melbourne, Australia.
authors.forename: Robyn
authors.initials: R
authors.lastname: Larsen
authors.affiliation: Baker IDI Heart and Diabetes Institute, Melbourne, Australia.
authors.forename: Parneet
authors.initials: P
authors.lastname: Sethi
authors.affiliation: Baker IDI Heart and Diabetes Institute, Melbourne, Australia.
authors.forename: Jessica
authors.initials: J
authors.lastname: Occleston
authors.affiliation: Department of Public Health and Clinical Medicine, Umeå University, Umeå, Sweden.
authors.forename: Jenny
authors.initials: J
authors.lastname: Hernestål-Boman
authors.affiliation: The Academic Unit for Psychiatry of Old Age, Department of Psychiatry, University of Melbourne, Melbourne, Australia.
authors.forename: Kathryn A
authors.initials: KA
authors.lastname: Ellis
authors.affiliation: Baker IDI Heart and Diabetes Institute, Melbourne, Australia Central Clinical School, Monash University, Melbourne, Australia School of Population Health, The University of Queensland, Brisbane, Australia Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Australia.
authors.forename: Neville
authors.initials: N
authors.lastname: Owen
authors.affiliation: Baker IDI Heart and Diabetes Institute, Melbourne, Australia School of Sport Science, Exercise & Health, University of Western Australia, Perth, Australia Central Clinical School, Monash University, Melbourne, Australia School of Population Health, The University of Queensland, Brisbane, Australia Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Australia School of Exercise & Nutrition Sciences, Deakin University, Melbourne, Australia Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, Australia Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Australia.
authors.forename: David W
authors.initials: DW
authors.lastname: Dunstan
mesh_terms: D000368:Aged; D001786:Blood Glucose / Q000378:metabolism; D001794:Blood Pressure; D003071:Cognition; D018592:Cross-Over Studies; D004295:Dihydroxyphenylalanine / Q000097:blood; D005221:Fatigue / Q000517:prevention & control*; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008734:Methoxyhydroxyphenylglycol / Q000031:analogs & derivatives / Q000097:blood; D008875:Middle Aged; D009765:Obesity / Q000097:blood / Q000503:physiopathology / Q000523:psychology*; D050177:Overweight / Q000097:blood / Q000503:physiopathology / Q000523:psychology*; D010865:Pilot Projects; D057185:Sedentary Behavior; D016138:Walking
chemical_list: D001786:Blood Glucose; D008734:Methoxyhydroxyphenylglycol; D004295:Dihydroxyphenylalanine; C010117:3,4-dihydroxyphenylglycol
keywords: OCCUPATIONAL & INDUSTRIAL MEDICINE; PREVENTIVE MEDICINE; SPORTS MEDICINE