Life expectancy of people could rise by two years, if they would spend sitting on a chair less than three hours per day, U.S. researchers have calculated. Also, if people would reduce the time spent watching television daily to two hours, they may prolong their life by 1.4 years, same scientists say in the online journal BMJ Open. But experts say that the U.S. researchers estimates, based on five separate studies, conducted on different groups are not accurate enough to thwart the risks of personal nature, inform bbc.co.uk.
Professor David Spiegelhalter, expert in risk calculating at the Cambridge University, said: “This is a study of people and does not tell individual people how much better is it for them if they don’t sit on a couch.” “It seems plausible that if younger generations would exercise more, they could live longer, on average,” he added. “But very few of us spend less than three hours a day sitting so we are talking about a very optimistic target,” he said. Adults are advised to have at least two and a half hours of gymnastic exercises with medium degree of difficulty, such as cycling or walking, every week, and also exercises of greater difficulty, such as lifting weights. But, considers the scientist, if subjects work in an office and sit for hours, they could be classified as sedentary, despite the fact that they exercise. More and more studies show that we are less healthy as we spend more time sitting on the chair. Several studies have linked sitting and long hours of watching television with heart disease and diabetes, and also the overall risk of dying prematurely. This link between the two elements is not necessarily a causal one.
The study which linked the sedentary living with life expectancy reduction was performed on a large sample of subjects – 167,000 people – but did not take into account their lifestyle. Thus, it is unclear how many of them had health problems before the study and data on hours spent seated or lying on the couch watching TV were provided by the individuals studied, which relies solely on their memory. Dr. Peter Katzmarzyk and Professor I-Min Lee, who conducted the study, said that their discovery is purely theoretical. They believe that the very fact to suggest that physical inactivity leads to health problems is a warning in itself.
Natasha Stewart, assistant at the British Heart Foundation, said: “This study only suggests the causal link between physical inactivity and lower life expectancy. Also, the study is about U.S. population, so for an estimate for the UK population further studies are necessary”. “However, it emphasizes what we already knew about sedentary behavior – that is a risk factor for heart. And UK medical indications even suggest for people to not spend much time sitting down,” said Natasha Stewart.
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