A 20 minute walk each day is enough to reduce an individual's risk of early death, according to a recent study.
Researchers from the University of Cambridge found that twice as many deaths may be attributable to lack of physical activity compared with the number of deaths attributable to obesity, but that just a modest increase in physical activity could have significant health benefits.
"This is a simple message: just a small amount of physical activity each day could have substantial health benefits for people who are physically inactive," Ulf Ekelund, who led the study, said in a statement. "Although we found that just 20 minutes would make a difference, we should really be looking to do more than this -- physical activity has many proven health benefits and should be an important part of our daily life."
Physical inactivity has been consistently associated with an increased risk of early death, as well as being associated with a greater risk of diseases such as heart disease and cancer. Although it may also contribute to an increased body mass index (BMI) and obesity, the association with early death is independent of an individual's BMI.
For the study, researchers analyzed data from more than 334,000 men and women across Europe participating in the European Prospective Investigation into Cancer and Nutrition (EPIC) Study. They researchers measured height, weight and waist circumference, and used self-assessment to measure levels of physical activity to find the link between physical inactivity and premature death, and its interaction with obesity.
They found that the greatest reduction in risk of premature death occurred in the comparison between inactive and moderately inactive groups, judged by combining activity at work with recreational activity; just under a quarter (22.7 percent) of participants were categorized as inactive, reporting no recreational activity in combination with a sedentary occupation.
The researchers estimate that doing exercise equivalent to just a 20 minute brisk walk each day -- burning between 90 and 110 calories -- would take an individual from the inactive to moderately inactive group and reduce their risk of premature death by between 16 to 30 percent. The impact was greatest amongst normal weight individuals, but even those with higher BMI saw a benefit.
Using the most recent available data on deaths in Europe the researchers estimate that 337,000 of the 9.2 million deaths amongst European men and women were attributable to obesity (classed as a BMI greater than 30): however, double this number of deaths (676,000) could be attributed to physical inactivity.
The findings are detailed in the American Journal of Clinical Nutrition.
