Citerank: (9) 348689Encourage physical activity in daily lifeThe Chief Medical Officer’s report (2011) recommends that adults aged 19-64 years undertake 150 minutes of moderate intensity physical activity per week in bouts of 10 minutes or more. [1]565CA4D9, 352521Not building exercise into daily life A primary cause of the rise in obesity in the UK in recent decades has been a decline in energy expended rather than rise in energy intake; with the changing pattern towards more sedentary lifestyles appearing to be a key factor in this.555CD992, 371611Changing patterns of physical activityTechnological development and urbanisation bring significant shifts in the patterns of daily activity that can reduce the amount of energy people expend in their normal daily routines.555CD992, 371615Self-reported physical activity is increasingThe number of people who are self-reporting as meeting the government's recommendation of taking 30 minutes vigorous exercise five times a week rose from 26.5 per cent to 37.5 per cent between 1997 and 2012. [3]13EF597B, 399668Encourage physical activity in daily lifeBuild exercise into daily life to promote energy balance. Adults are recommended to take part in 150 minutes of moderate intensity activity every week.565CA4D9, 399897Changing patterns of physical activityTechnological development and urbanisation bring significant shifts in the patterns of daily activity that can reduce the amount of energy people expend in their normal daily routines.555CD992, 399908Not building exercise into daily life The primary cause of the rise in obesity in the UK in recent decades has not been a decline in energy expended rather than rise in energy intake; with the changing pattern towards more sedentary lifestyles appearing to be a key factor in this.555CD992, 399922Increasingly sedentary lifestylesSedentary behaviour is not simply a lack of physical activity but is a cluster of individual behaviours in which sitting or lying is the dominant mode of posture and energy expenditure is very low. Research suggests that sedentary behaviour is associated with poor health in all ages independent of the level of overall physical activity. Spending large amounts of time being sedentary may increase the risk of some adverse health outcomes, even among people who are active at the recommended levels.555CD992, 399933Self-reported physical activity is increasingThe number of people who are self-reporting as meeting the government's recommendation of taking 30 minutes vigorous exercise five times a week rose rose from 26.5 per cent to 37.5 per cent between 1997 and 2012. [3]13EF597B

BACKGROUND: Sedentary behavior is a risk factor for cardiometabolic disease. Regularly interrupting sedentary behavior with activity breaks may lower this risk.

OBJECTIVE: We compared the effects of prolonged sitting, continuous physical activity combined with prolonged sitting, and regular activity breaks on postprandial metabolism.

DESIGN: Seventy adults participated in a randomized crossover study. The prolonged sitting intervention involved sitting for 9 h, the physical activity intervention involved walking for 30 min and then sitting, and the regular-activity-break intervention involved walking for 1 min 40 s every 30 min. Participants consumed a meal-replacement beverage at 60, 240, and 420 min.

RESULTS: The plasma incremental area under the curve (iAUC) for insulin differed between interventions (overall P < 0.001). Regular activity breaks lowered values by 866.7 IU · L(-1) · 9 h(-1) (95% CI: 506.0, 1227.5 IU · L(-1) · 9 h(-1); P < 0.001) when compared with prolonged sitting and by 542.0 IU · L(-1) · 9 h(-1) (95% CI: 179.9, 904.2 IU · L(-1) · 9 h(-1); P = 0.003) when compared with physical activity. Plasma glucose iAUC also differed between interventions (overall P < 0.001). Regular activity breaks lowered values by 18.9 mmol · L(-1) · 9 h(-1) (95% CI: 10.0, 28.0 mmol · L(-1) · 9 h(-1); P < 0.001) when compared with prolonged sitting and by 17.4 mmol · L(-1) · 9 h(-1) (95% CI: 8.4, 26.3 mmol · L(-1) · 9 h(-1); P < 0.001) when compared with physical activity. Plasma triglyceride iAUC differed between interventions (overall P = 0.023). Physical activity lowered values by 6.3 mmol · L(-1) · 9 h(-1) (95% CI: 1.8, 10.7 mmol · L(-1) · 9 h(-1); P = 0.006) when compared with regular activity breaks.

CONCLUSION: Regular activity breaks were more effective than continuous physical activity at decreasing postprandial glycemia and insulinemia in healthy, normal-weight adults.

Sedentary (sitting) behaviours are ubiquitous in modern society. We conducted a systematic review and meta-analysis to examine the association of sedentary time with diabetes, cardiovascular disease and cardiovascular and all-cause mortality.

METHODS: Medline, Embase and the Cochrane Library databases were searched for terms related to sedentary time and health outcomes. Cross-sectional and prospective studies were included. RR/HR and 95% CIs were extracted by two independent reviewers. Data were adjusted for baseline event rate and pooled using a random-effects model. Bayesian predictive effects and intervals were calculated to indicate the variance in outcomes that would be expected if new studies were conducted in the future.

RESULTS: Eighteen studies (16 prospective, two cross-sectional) were included, with 794,577 participants. Fifteen of these studies were moderate to high quality. The greatest sedentary time compared with the lowest was associated with a 112% increase in the RR of diabetes (RR 2.12; 95% credible interval [CrI] 1.61, 2.78), a 147% increase in the RR of cardiovascular events (RR 2.47; 95% CI 1.44, 4.24), a 90% increase in the risk of cardiovascular mortality (HR 1.90; 95% CrI 1.36, 2.66) and a 49% increase in the risk of all-cause mortality (HR 1.49; 95% CrI 1.14, 2.03). The predictive effects and intervals were only significant for diabetes.

CONCLUSIONS/INTERPRETATION: Sedentary time is associated with an increased risk of diabetes, cardiovascular disease and cardiovascular and all-cause mortality; the strength of the association is most consistent for diabetes.