Engaging in physical activity for at least one hour a day may eliminate the increased risk of death associated with 8 hours or more of sitting every day.
The finding comes from an article series in The Lancet, which has been published ahead of the Summer Olympic Games. The authors warn that too little has been done to combat the issue of physical inactivity since the Olympics in 2012, with around 25% of adults globally still failing to meet physical activity recommendations.
One article form the series reports on the association between sitting time, physical activity and risk of death. Lead author Ulf Ekelund (Norwegian School of Sports Sciences, Norway and the University of Cambridge, UK) and colleagues looked at data for more than 1 million people across 16 previous studies. The participants were mainly aged over 45 years and from the USA, Australia and western Europe.
During a follow-up period of two to 18 years, people who sat for at least 8 hours a day and engaged in low amounts of physical activity had a 9.9% risk of dying. This compared with a 6.8% risk among people who sat for less than four hours a day and engaged in physical activity for at least one hour a day.
However, the study also showed that the increased risk of death among people who sat for 8 hours a day was eliminated by doing at least one hour a day of “moderate intensity” exercise. One hour of walking at 5.6 km/h or cycling at 16 km/h, for example, was sufficient to offset the ill effects of sitting for this amount of time.
Ekelund and team also found that sitting watching TV for more than three hours a day was associated with an increased risk of death, apart from among the most active individuals.
The increased risk was slightly greater than that linked to total sitting time, possibly because TV watching may be a marker for a generally less healthy lifestyle, including being less likely to engage in physical activity. People may also be more likely to eat unhealthy snacks while they watch TV.
There has been a lot of concern about the health risks associated with today’s more sedentary lifestyles,”
“Our message is a positive one: it is possible to reduce – or even eliminate – these risks if we are active enough, even without having to take up sports or go to the gym.”
Ulf Ekelund (Norwegian School of Sports Sciences, Norway and the University of Cambridge, UK.
Ekelund acknowledges that for many commuters with desk-based jobs, it is often not possible to escape sitting for long periods.
“For these people in particular, we cannot stress enough the importance of getting exercise, whether it’s getting out for a walk at lunchtime, going for a run in the morning or cycling to work. An hour of physical activity per day is the ideal, but if this is unmanageable, then at least doing some exercise each day can help reduce the risk,” he advises.
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