While the WHO has just unveiled its new guidelines on physical activity and sedentary lifestyles, a study conducted in parallel reveals that around 30 to 40 minutes of moderate to vigorous physical activity per day allows "only" reduce the association between a sedentary lifestyle and the risk of death.

At a time when COVID-19 is forcing many people to stay at home, it is all the more important for everyone, regardless of age and ability, to have very regular physical activity because all types of movement are important. Numerous studies have already shown that regular physical activity is essential to prevent and better manage heart disease, type 2 diabetes and cancer, as well as to reduce symptoms of depression and boost brain health. According to its new guidelines, the World Health Organization (WHO) now recommends at least 150 to 300 minutes per week of moderate-to-sustained aerobic activity for adults.

 These recommendations are in line with those of a recent study published in the British Medical Journal, namely that increasing physical activity can counter the risk of premature death linked to long periods of inactivity. The authors of the study asked themselves this question: what frequency of physical exercise is really necessary to counter the negative impact on health of a day spent sitting in front of a computer? About 30 to 40 minutes a day depending on their findings. So up to 40 minutes of “moderate to vigorous intensity physical activity” each day is about the right amount to balance 10 hours of inactivity.

Any physical practice is recommended

By physical activity, researchers mean any type of activity: going up the stairs instead of taking the elevator, a walk around the block, gardening or household chores, a run or bike, a workout by high intensity intervals or team sport. Their finding is based on a meta-analysis of nine studies involving a total of 44,370 people from four different countries who wore some form of fitness tracker. This reveals that the risk of death in people with a more sedentary lifestyle increases as the time spent in moderate to vigorous intensity physical activity decreases.

"In people doing about 30 to 40 minutes of moderate to vigorous physical activity, the association between a high sedentary time and risk of death is not significantly different from those with low sedentary periods", write the researchers in the article. In other words, the fact of practicing a fairly intensive physical activity (cycling, brisk walking, gardening) makes it possible to compensate for the harm to health of a prolonged sitting position. For people who can, they urge "to exceed these weekly recommendations" to do more than simply counter the harm of sedentary behavior.

Sedentary lifestyle: a threshold difficult to establish but to counterbalance

“Although the new guidelines reflect the best available science, there are still gaps in our knowledge. We still don't know, for example, where exactly the time limit is when sitting. These guidelines are timely, given that we are in the midst of a global pandemic that has confined people to their homes for long periods of time and encouraged an increase in sedentary behavior, ”says one of the study's authors, Prof. Emmanuel Stamatakis from the University of Sydney. However, WHO statistics show that one in four adults and four in five adolescents do not get enough physical activity.

Globally, she estimates it costs $ 54 billion in direct health care. The agency also says it would be possible to prevent up to 5 million deaths per year if the world's population were more active. For their part, the researchers recommend that people who are sedentary for long periods due to work and transport to strive to achieve the highest recommended level of physical activity of 300 minutes of moderate to vigorous physical activity per week. . “Our work may inform the development of future recommendations on physical activity and sedentary lifestyle by the WHO and other public health authorities,” they conclude.