Programs focused on changing lifestyle and sedentary behaviours help reduce sedentary (sitting) time

Martin A, Fitzsimons C, Jepson R et al. Interventions with potential to reduce sedentary time in adults: Systematic review and meta-analysis British Journal of Sports Medicine. 2015; 0:1-10.

Review question

Do programs aiming to reduce adults’ sedentary time actually work?

Do the same programs reduce the risk of poor health?

Background

There is growing concern that poor health in adults is associated with time spent in sedentary behaviours, such as sitting or lying down. Previous research shows that too much sedentary time increases risk of heart disease, stroke, type 2 diabetes and mental illnesses. The purpose of this research was to measure the effectiveness of programs aiming to reduce sedentary time and the impact of these programs on health.

How the review was done

This is a meta-analysis of 34 randomized controlled trials conducted between 1998 and 2014, including over 5800 adult participants. The 34 studies all included some type of program aiming to reduce sedentary time, such as:

• Programs focused solely on promoting physical activity (e.g. walking)
• Programs focused solely on reducing sedentary behaviours (e.g. education about taking breaks during prolonged sitting time)
• Programs focused on promoting both physical activity and reducing sedentary time
• Programs focused solely on changing lifestyle behaviours (e.g. education about healthy eating, physical activity, health behaviour counseling)

The impact of the programs were measured  in different ways, including:

• Self-reported total sitting time and daily sedentary behaviours (e.g. at work, while driving or commuting, or in leisure activities)
• Using devices that measure activity level
• Indicators of health risks, such as blood glucose levels, blood pressure, and rates of anxiety and depression in participants

The researchers compared these measurements to people in a control group who did not participate in any type of activity-based program. The duration of the programs ranged from less than 3 months to over 6 months. Follow-up ranged from less than 3 months to over 12 months.

What the researchers found

Programs focused solely on reducing sedentary behaviours (SB) were the most effective (reduced SB by 42 min/day). Programs focused solely on changing lifestyle behaviours were also effective (reduced SB by 24 min/day). Programs just promoting physical activity, or promoting physical activity while reducing sedentary behaviours did not significantly reduce sedentary time. Short-term programs (3 months or less) were the most effective in reducing daily sedentary time (reduced by 48 min/day). However, a 12 month follow-up found that these benefits were not maintained long-term. It was not possible to determine whether reducing SB reduced health risks, such as heart disease, stroke, type 2 diabetes, or mental illness.  

Conclusion

Programs focused solely on reducing sedentary behaviour and programs which promote lifestyle changes help reduce sedentary time in the short term. More research is needed to determine the health benefits of reducing adults’ sedentary time.