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Less sitting down can boost life expectancy

Cutting down on the amount of time spent sitting in front of the television may boost a person's life expectancy by 1.4 years, a US study suggests.

Furthermore, restricting the time spent sitting down every day to less than three hours could add a two-year extension onto a person's life.

A study published in BMJ Open analysed data collected for the National Health and Nutrition Examination Survey (NHANES) for 2005/6 and 2009/10 on the general health and lifestyle of 167,000 US adults.

Basing their findings on five population studies, researchers estimated deaths from all causes linked to sitting time and TV viewing were 27% and 19%, respectively.

However, the study was unable to predict individual risk associated with time spent sitting down.

The researchers have stressed the study does not prove a causal relationships between a sedentary - low physical activity - lifestyle and being unhealthy.

“The results of this study indicate that extended sitting time and TV viewing may have the potential to reduce life expectancy in the USA,” said the researchers.

“Given that the results from objective monitoring of sedentary time in NHANES has indicated that adults spend an average of 55% of their day engaged in sedentary pursuits, a significant shift in behaviour change at the population level is required to make demonstrable improvements in life expectancy.”

NHS workers should hold back from recommending “safe levels” of sedentary behaviour until further research has been carried out, the researchers claim.