Lack of exercise may be twice as deadly as obesity, a new study finds. The good news is that as little as 20 minutes of brisk walking each day is enough to reduce the risk of early death by as much as 30 percent, the Cambridge University researchers reported this week in the American Journal of Clinical Nutrition.
Past research has consistently demonstrated a link between physical inactivity and an increased risk of early death, as well as a greater risk of chronic conditions such as heart disease and cancer. Although it may also contribute to an increased body mass index (BMI) and obesity, the new findings suggest that the association between sedentary behavior and early death may be independent of body weight/BMI.
To measure the link between physical inactivity and premature death, and its interaction with obesity, the Cambridge team analyzed data from 334, 161 men and women across Europe participating in the European Prospective Investigation into Cancer and Nutrition (EPIC) Study. Between 1992 and 2000, the researchers measured height, weight and waist circumference, and used self-assessment to measure levels of physical activity. The participants were then followed up over 12 years, during which 21, 438 participants died.
The results showed that a moderate amount of physical activity, compared with no activity, was the key to lowering the risk of premature death. Just a modest increase in physical activity could make a big difference, the especially among inactive people.
The researchers found the greatest reductions in risk of early death when they compared inactive and moderately active participants. Overall, 22.7 percent of participants as inactive because they reported having no recreational activity and were occupied in sedentary jobs.
According to the team’s calculations, exercise that burns between 90 and 110 calories a day could reduce the risk of an early death by between 16 percent and 30 percent. The effect of moderate exercise was greatest among normal weight people, but even overweight and obese people saw a benefit, they found.
Using the most recent data on deaths in Europe, the team estimated that 337,000 of the 9.2 million deaths of European men and women were linked to obesity. However, twice that number of deaths could be connected to lack of exercise.
The study delivers a simple message, says first author Dr. Ulf Ekelund, a sport medicine professor for the Medical Research Council (MRC) Epidemiology Unit at the University of Cambridge in the UK: “Just a small amount of physical activity each day could have substantial health benefits for people who are physically inactive.”
From a public health perspective, it is as important to increase levels of physical activity as it is to reduce the levels of obesity — maybe even more so, said Dr. Ekelund. “We estimated that eradicating physical inactivity in the population would reduce the number of deaths twice as much as if obesity was eradicated,” he said. However, he added, while 20 minutes of brisk walking a day can make a difference, we should really do more, as “physical activity has many proven health benefits and should be an important part of our daily life.”