A population-based study that ran for 9.9 years has found that couch potatoes- and desk workers- have nothing to worry about. The study followed 6, 397 women with a mean age of 52.5 years and a mean sitting time of 5.4h/d. Researchers found no significant association between sitting time and heart disease incidence at a low 1.17 risk.
Adults are only not getting enough exercise, they are also sitting around too much. Decades of research have found that sedentary behaviour, like sitting for long periods increases the risk for chronic diseases in adults and even exercise does not appear to help. People engaged in sedentary behaviors have a 90% risk of dying from heart disease, a 2012 review of four studies found. Three of those studies found a significant association between TV viewing time and heart disease risk, while one study found heart disease risk higher in women who sat for 16 h/d compared with those who sat for less than four hours.
This study investigated the association of sitting time and heart disease incidence among mid-aged Australian women.
The researchers enrolled women born in 1921-26, 1946-51, and 1973-78. But the focus was on women born in 1946-51 who completed surveys in 1996, 1998 and every three years thereafter. The analysis also included those who lived around New South Wales and Queensland and completed survey three in 2001, totaling to around 6, 739 women. The surveys included questions about the women's total time spent sitting, including watching TV, driving, working at a desk and visiting with friends. Other factors investigated were demographics and lifestyle factors including alcohol consumption, physical activity and smoking. Women with pre existing heart disease and stroke history were excluded.
In the nine year follow-up there were 177 (a 1.17 risk), cardiovascular events that occurred, four of which were fatal but the researchers found no significant association between sitting time and heart disease among middle-aged women, in contradiction to previous studies. The women spent an average of 5.4 h/d sitting. Women with the highest sitting time were likely to be more educated and obese and less physically active.
The contradiction may be in that the participants in this study are less sedentary, with the highest sitting time being 8.4 h/d. It is quite possible that the mean sitting time was too low to detect a significant effect on heart disease. Despite the women being followed for about 9.9 years, sitting time may take longer to impact heart disease.
In light of these surprising findings, there is bound to be a collective sigh of relief across the globe. But it might be too soon to become idle. While the evidence says there is no correlation between sitting time and heart disease, it is far from conclusive. Further epidemiological studies are still needed to confirm or refute these findings. In any case, the significance of physical activity and minimising sedentary behaviors cannot be underestimated.
Source :
https://ijbnpa.biomedcentral.com/articles/10.1186/1479-5868-10-55