NEW YORK, March 27 — A new large-scale US study has found more evidence to suggest that replacing sedentary time with physical activity could lower the risk of death.
Carried out by researchers at the American Cancer Society, the new study looked at 92,541 participants and analysed their reported sedentary time and activity levels, including light physical activity and moderate/vigorous physical activity, over a 14-year period.
The findings, published in the American Journal of Preventive Medicine, showed that for participants who were least active at the start of the study — engaging in 17 minutes per day of moderate to vigorous physical activity — replacing 30 minutes sitting time per day with light physical activity appeared to reduce the risk of death by 14 per cent. Replacing this sitting time with moderate to vigorous physical activity brought even bigger benefits, reducing the risk of death by 45 per cent.
For those who were already moderately active, replacing 30 minutes of sedentary time with light physical activity reduced the risk of death by six percent, and replacing it with 30 minutes of moderate to vigorous physical activity reduced it by 17 per cent.
However, for the most active participants, who did more than 38 minutes per day of moderate/vigorous physical activity, replacing sitting time with more activity, no matter what the intensity, was not associated with a reduction in mortality risk.
Regular moderate- to vigorous-intensity physical activity has already been associated with a lower risk of cardiovascular disease, certain cancers, and premature death, with the researchers also finding that the participants who reported engaging in exercise of this intensity tended to be slimmer, non-smokers, and have a higher level of education.
In addition, the amount of time spent sedentary has been associated in many previous studies with a higher risk of death and disease.
The researchers note that the new study did have some limitations, including using self-reports on physical activity and sitting time which can be subject to errors, however they conclude that, “These findings suggest that the replacement of modest amounts of sitting time with even light physical activity may have the potential to reduce the risk of premature death among less active adults.” — AFP-Relaxnews
