Nearly half of SG adults have too much sedentary time

Around half of Singapore’s population spend a considerable amount of time in sedentary behaviour, with nearly 20 percent failing to reach the minimum requirements for weekly physical activity, leading to worse health-related quality of life (HRQoL), according to a recent study.

“Policymakers should allocate more resources to promoting moderate physical activity and encouraging the breaking up of prolonged sedentary periods for middle- and high-income groups, especially during working hours,” the researchers said. “For those in the lower-income groups, it would be prudent to encourage more leisure-time exercise.”

The study included 2,867 participants (aged ≥18 years, 51.6 percent women). Using the WHO’s Global Physical Activity Questionnaire, 83.4 percent of participants were found to have sufficient weekly physical activity, defined as at least 150 minutes of moderate physical activity, 75 minutes of vigorous physical activity, or an equivalent combination of both intensities. [BMC Public Health 2021;21;1939]

Notably, participants also reported high levels of sedentary activity and spent a median of 6 sedentary hours per day. Moreover, almost half (47.7 percent) of respondents said they had ≥7 hours of sedentary time per day.

The researchers then performed logistic regression analyses to identify correlates of both physical activity and sedentary behaviour. They found that individuals aged ≥65 years were more than twice as likely to be insufficiently active (odds ratio [OR], 2.5, 95 percent confidence interval [CI], 1.3–4.9; p=0.01). In contrast, older adults were significantly less likely to report <7 hours of sedentary behaviour per day (OR, 0.5, 95 percent CI, 0.3–0.9; p=0.02).

Participants aged 50–65 years (OR, 0.6, 95 percent CI, 0.4–0.9; p=0.01) and 35–49 years (OR, 0.7, 95 percent CI, 0.5–1.0; p=0.04) were likewise less likely to report high levels of daily sedentary activity. All age analyses used 18–34-year-olds as reference.

Aside from age, income also emerged as a significant indicator of sedentary behaviour. Relative to the lowest bracket, those earning SGD 2,000–3,999 (OR, 1.9, 95 percent CI, 1.3–2.6; p=0.001) and SGD 4,000–5,999 (OR, 1.9, 95 percent CI, 1.2–3.0; p=0.01) per month were nearly twice as likely to report having ≥7 hours of sedentary behaviour per day.

Such an effect was even stronger among those earning SGD 6,000–9,999 (OR, 2.6, 95 percent CI, 1.4–4.7; p=0.001) and SGD ≥10,000 (OR, 4.4, 95 percent CI, 2.2–8.7; p<0.001) per month.

In turn, such low levels of physical activity led to worse HRQoL. In particular, physical component scores were significantly worse among participants who were insufficiently activity on a weekly basis (B, –2.5, 95 percent CI, –3.5 to –1.4; p<0.001). No such effect on mental component scores was reported. Sedentary behaviour was also unrelated to both physical and mental components of HRQoL.

“The sample for the present study was representative of the resident population of Singapore, and the results are therefore generalizable,” the researchers said, noting important limitations including its cross-sectional design, the inability to robustly account for confounders introduced by the pandemic, and the use of self-reported physical activity data.

“Future studies are therefore encouraged to utilize accelerometers as an objective measure to examine both physical activity and sedentary behaviour,” they added.