A sedentary lifestyle can increase one’s risk of death, but it may be countered by just 20 to 25 minutes of physical activity per day, according to a study published online in the British Journal of Sports Medicine.
Regardless of the amount of time spent sitting down each day, larger daily totals of physical activity are associated with a lower risk of death, according to the research.
Adults in affluent countries sit down for nine to 10 hours a day on average, primarily during work hours. Furthermore, the researchers clarify that a severely sedentary lifestyle is linked to an increased chance of passing away.
A significant amount of earlier research on the advantages of physical activity in reducing prolonged sitting has relied on aggregated data, which invariably leads to a generalised approach, they suggested.
To try and overcome this, the researchers pooled individual participant data from four groups of people fitted with activity trackers to find out whether physical activity might modify the association between sedentary time and death, and vice versa, and what amount of physical activity and sitting time might influence risk.
They included Individual participant data collected between 2003 and 2019 from the Norwegian Tromso Study 2015-16; the Swedish Healthy Ageing Initiative (HAI) 2012-19; the Norwegian National Physical Activity Survey (NNPAS) 2008- 09; and the US National Health and Nutrition Examination Survey (NHANES) 2003-06.
Just short of 12,000 people aged at least 50 were included in the analysis. They had a minimum of 4 days of 10 daily hours of activity tracker records, had been monitored for at least 2 years, and had provided details of potentially influential factors: their sex, educational level, weight, height, smoking history, alcohol intake, and whether they had current and/or previous cardiovascular disease, cancer and/or diabetes.
In all, 5943 people spent fewer than 10.5 hours sitting down every day; 6042 clocked up 10.5 or more sedentary hours.
More than 22 daily minutes of moderate to vigorous physical activity was associated with a lower risk of death.
While a higher amount of moderate to vigorous physical activity was associated with a lower risk of death, irrespective of the amount of sedentary time, the association between sedentary time and death was largely influenced by the amount of moderate to vigorous physical activity.
For example, an extra 10 minutes a day was associated with a 15 per cent lower risk of death in those spending fewer than 10.5 sedentary hours, and a 35 per cent lower risk among those spending more than 10.5 sedentary hours, every day.
Light-intensity physical activity was only associated with a lower risk of death among highly sedentary people (12+ daily hours). This is an observational study, and as such, can’t establish cause and effect. The researchers acknowledge that they weren’t able to repeat measures of physical activity and sedentary hours, precluding any changes in either over time.
Potentially influential factors, such as diet, mobility issues, and general health weren’t accounted for either. Activity trackers may not correctly classify all activity types and their corresponding intensity–cycling, resistance exercises, gardening, for example.
Nevertheless, the researchers conclude: “Small amounts of MVPA [moderate to vigorous physical activity] may be an effective strategy to ameliorate the mortality risk from high sedentary time, where accumulating more than 22 mins of MVPA eliminates the risk of high sedentary time.
“Efforts to promote physical activity may have substantial health benefits for individuals.”
(with inputs from ANI)
