A long Danish studyrecently published in European Heart Journalreached conclusions that seem paradoxical: while physical activity performed during leisure time was associated with a lower risk of cardiovascular problems and death, the one made during work turned out to be linked to a greater probability of these negative outcomes. Let’s understand the survey and its results.
The research was conducted with 104 046 volunteers between 20 and 100 years old. The participants answered questionnaires about what they did during leisure and work hours. The frequency of physical activity of each one was classified as low, moderate, high or very high.
Over ten years, 9,846 participants died (9.5% of the total) from various causes. The researchers also recorded serious cardiovascular events in 7913 people (7.6%). They include fatal and nonfatal heart attacks and strokes.
The scientists also considered issues such as age, sex, lifestyle, health conditions and socioeconomic levels of the participants, to prevent them from interfering with the conclusions. “This means that the relationships we found are not explained by any of these factors,” says Andreas Holtermann, one of the study’s authors and a professor at the National Research Center for the Working Environment in Copenhagen, Denmark.
According to this investigation, frequencies of moderate, high and very high physical activity during leisure time are associated with reductions of 26%, 41% and 40% in the risk of death, respectively. On the other hand, high or very high volumes of physical activity at work were linked to 13% and 27% increases in the risk of death, respectively.
The study didn’t examine the reasons behind these wildly different data, but Holtermann hazards a guess. According to him, more physical jobs are not equal to a sport. “Being lifting weights for many hours increases blood pressure continuously, which is related to the risk of heart disease,” I argue. And the employee does not always have the autonomy to stop and rest when necessary. Physical exercise during leisure time is more adjustable.
Paulo Guerra, president of the Brazilian Society of Physical Activity and Health (SBAFS), reinforces that the absence of adequate control can help explain the data. “In occupational physical activities, sometimes there is a lack of planning, professional guidance and even care with the use of appropriate clothing”, he explains. “A mason, for example, cannot determine the amount of weight to be lifted, rest time and even body gestures”, he concludes. Not to mention the stress of any service.
Another possibility suggested by Holtermann is that certain physical activities at work do not increase the heart rate to the point of bringing clear benefits. But they still leave employees feeling tired and believing they don’t need to exercise in their spare time.
According to the Danish expert, one idea is to reorganize occupational activity so that it, let’s say, mimics the beneficial aspects of leisure exercise. In a press release for this research, the European Society of Cardiology states that “various approaches are being tested, such as rotating between workstations on a production line so that employees make a healthy mix between sitting, standing and lifting weights during a shift”, explains the entity.
“We need to find ways to make active work good for health”, concludes Holtermann.
It is only worth mentioning that this is an observational research, which only associates factors. Therefore, it is not possible to be sure whether physical activity actually causes the increased risk of cardiovascular events — or whether there is something unknown behind this relationship.