In an increasingly busy world, sedentary behaviour – that is sitting for long periods of time – has become common.
People often work long hours at their desk and wind down with time spent in front of the TV. Furthermore, commuting via car is common so people may transfer from the car, to the office desk, back to the car and then home to the couch in a day with very little physical activity in between. Lack of physical activity and increased time spent sitting has been found to increase the risk of a number of chronic diseases and the risk of premature death. It’s known that increasing levels of physical activity can improve health outcomes and reduce the incidence of many chronic diseases. What’s less known, however, is whether or not increasing levels of physical activity can counteract the detrimental effects of large amounts of time spent sitting. Researchers reviewed the evidence around the association between sedentary behaviour and physical activity levels and risk of death from all causes.
Researchers looked at studies that recorded physical activity levels, time spent sitting and cause of death, as well as disease- specific death rates. Sedentary behaviour was measured in daily sitting time and TV- viewing time. Physical activity levels were assessed in the studies via self-reported questionnaires. Researchers compared the data from those who had different amounts of sitting times and varying levels of physical activity.
The results showed that, in those people with the highest levels of physical activity, there was no significant association between time spent sitting and premature death. In this group, however, an association remained, albeit reduced a little, for those who had high levels of TV- viewing time. For those with moderate levels of physical activity there was still an association between sitting time and premature death, however this was reduced according to the level of physical activity undertaken compared with those in the least active group.
The findings of this review suggest that high levels of physical activity, which was about 60 – 75 minutes per day at moderate intensity, significantly reduced the increased risk of death associated with long periods of time spent sitting. While this level of physical activity may be unattainable, the good news is that lower levels of physical activity still lowered the risk. These findings add further weight to the bene ts of getting up and active throughout the day. Even incidental exercise can help increase your daily physical activity levels. So take the stairs instead of a lift; walk, cycle or catch public transport to work instead of driving; and try to get up out of your chair at regular intervals at work throughout the day so that you don’t spend the whole day seated.
Reference: Ekelund, U et al. (2016). Does physical activity attenuate, or even eliminate, the detrimental association of sitting time with mortality? A harmonised meta-analysis of data from more than 1 million men and women. Lancet, 388, 1302-10.