Sitting has been billed as ‘the new smoking’, with a spate of research over the past five years highlighting the detrimental effects of a sedentary lifestyle.
Offering new hope for desk-bound office workers and couch potatoes, the University of Sydney-led research paper titled Sitting Time, Physical Activity, and Risk of Mortality in Adults was published in the Journal of the American College of Cardiology on Tuesday.
In a comprehensive long-term analysis, the researchers statistically modelled physical activity and sitting against death records of nearly 150,000 study participants aged 45 years and over and followed up over almost nine years.
They found that regular physical activity “effectively eliminated the association of sitting time” with premature and cardiovascular disease-related death.
Moderate-to-vigorous exercise in line with current guidelines is sufficient to counteract the harmful effect of spending long periods of time seated, the researchers said.
This study found that a minimum of 150 minutes of “moderate intensity” physical activity, or 75 minutes of “vigorous intensity” exercise per week was enough to eliminate sitting risks.
Australian public health authorities currently recommend at least 150 to 300 minutes exercise per week – or about 20-40 minutes a day.
The study emphasised the importance not only of reducing sitting time, but of incorporating regular physical activity throughout the day.
Replacing sitting with physical activity – but not standing – reduced the risk of death among ‘high sitters’ – people who sit more than six hours per day, the study found.
“In our study, sitting time was associated consistently with both overall premature mortality and cardiovascular disease mortality in the least physically active groups,” the study’s lead author Professor Emmanuel Stamatakis said.
“For example, people who were physically inactive and sat for more than eight hours per day had 107 per cent higher risk for cardiovascular death compared to those who did at least one hour physical activity per day and sat less than four hours.”
Professor Stamatakis said the findings would be useful for public health officials, healthcare workers, but also people who sit a lot, such as workers in office-based and other sedentary jobs.
“Any movement is good for health but physical activity of moderate to vigorous intensity – that is activities that get people out of breath – is the most potent and most time-efficient,” he said.
“Exercise and sports are a great way to be active but are not the only way – walking fast, climbing stairs, and cycling to get from place to place are only some of the many opportunities everyday life offers to move and even ‘huff and puff’ sometimes.”
How to reduce the health risks of excessive sitting
- Get at least 150 minutes of “moderate” exercise or 75 minutes of “vigorous” exercise per week
- Reduce sitting time and increase physical activity
- Replace sitting with walking and vigorous physical activity
- Avoid long periods (more than 30 minutes) of continuous unbroken sitting
- Make simple changes to daily habits, such as standing up on public transport and taking the stairs