Maintaining or increasing the level of activity in the middle of life, or even later, reduces the risk of death, says a major British study published BMJ.
However, an expert from the University of Ottawa believes that these results must be interpreted with caution.
Researchers at Cambridge University reported that 46% of deaths attributable to sedentary lifestyle can be avoided if the population participates every week in at least 150 minutes of moderate or high physical activity.
This is clearly not the first study linking physical activity with reduced risk of death, cardiovascular disease and certain types of cancer. This time, British researchers were more interested in influencing the risk of death fluctuation at the level of physical activity over time.
In a large European survey, data from nearly 15,000 participants was collected. The subjects were aged between 40 and 79 years. All forms of physical activity (or inactivity) are considered, whether they are sitting jobs or requiring physical effort or physical activities that are spent in leisure time.
Researchers have recorded 3148 deaths during the study, including 950 deaths from cardiovascular causes and 1091 deaths due to cancer.
Even taking factors such as diet, disease history, blood pressure and cholesterol levels, higher levels of body activity and increased body activity over time were associated with decreasing the risk of mortality.
A sedentary subject at the beginning of a study who increased the level of physical activity for the next five years to reach the minimum recommendations would reduce the risk of death from all causes by 24%, by 29%. risk of cardiovascular death and 11% risk of cancer death.
Sedentary subjects who started to move reduced the risk of death from all causes than people who were sitting in a sitting position. Participants with or without history of cancer or cardiovascular disease have achieved similar results.
However, respondents who were already very active and who were more active over the years were given the advantage, reducing the risk of mortality by 42%.
This study is "encouraging," said Yves Lajoie of the Ottawa University of Health Sciences, although the results must be interpreted with particular caution.
"When we use such databases instead of doing a longitudinal study, sometimes we risk copying too much data," he explained. When we look at those studies where important databases have been used, we can always suppress results. We must not take too fast. "
Given this, the benefits of physical exercise for health should not be questioned. Mr. Lajoie recalls that at the turn of the millennium, people are told that bodily activity will not add "a year to your life, but to your years of life".
"So there's someone who said that just because you're practicing, you will not live longer," he added. It is very likely that the exercise could extend the lives of some people. But to say or generalize tomorrow morning that exercise will prolong life for everyone, I'm not sure. "
He concluded that even the authors of the study recognize that their results can not necessarily be generalized to the entire population.
"Yes, well, probably, and I hope, because I'm doing a lot of work and hopefully adding life to my years, adding years of life. We hope we will not do all this for nothing," said Mr. Lajoie.