title: Effects of Breaking Sitting by Standing and Acute Exercise on Postprandial Oxidative Stress.
abstract: BACKGROUND
  Sedentary behavior, which includes sitting and TV viewing, has been identified as an independent risk factor for type 2 diabetes and cardiovascular disease. Breaking sedentary behavior improves metabolic health such as postprandial glycaemia and insulinemia. However, the mechanisms underlying this effect are unclear.
  
  
  OBJECTIVE
  Here, we examined whether breaking sitting by standing and acute exercise reduces postprandial oxidative stress.
  
  
  METHODS
  Fifteen participants performed 3 trials (sitting, standing, and exercise), each lasting 2 days, in a randomised order. On day one of sitting trial, participants sat in a chair. For the standing trial, the participants stood 6 times, for a 45-minute period each time. For the exercise trial, the participants walked or ran at approximately 60% of age-predicted maximum heart rate for 30 minutes. On day two of each trial, participants rested and consumed the standardised breakfast and lunch. Blood samples were collected in the morning and afternoon on day one, and fasting and at 2, 4, and 6 hours postprandially on day two.
  
  
  RESULTS
  The concentrations of serum derivatives of reactive oxygen metabolites (d-ROMs) measured at 4 hours (P = 0.064) and 6 hours (P = 0.071) tended to be higher than that in the fasting state in the sitting trial, but not standing and exercise trial (two-factor analysis of variance (ANOVA), trial × time interaction, P = 0.006).
  
  
  CONCLUSIONS
  Our results indicate the importance of reducing sitting time for improving postprandial oxidative stress status.
authors.affiliation: Faculty of Sport Sciences, Waseda University, Tokorozawa, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Takahashi
authors.affiliation: Faculty of Education, Tokyo Gakugei University, Koganei, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Miyashita
authors.affiliation: Dong-A Anti-Aging Research Institute, Dong-A University, Busan, South Korea.
authors.forename: Jong-Hwan
authors.initials: JH
authors.lastname: Park
authors.affiliation: Faculty of Sport Sciences, Waseda University, Tokorozawa, Japan.
authors.forename: Shizuo
authors.initials: S
authors.lastname: Sakamoto
authors.affiliation: Faculty of Sport Sciences, Waseda University, Tokorozawa, Japan.
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Suzuki
keywords: Cardiovascular Disease; Physical Activity; Postprandial Period; Redox; Sedentary Lifestyle