Exercise helps the heart, but can manual labor hurt?


May 12, 2021 – Not all exercises are created equal Playing sports The one that you get in your spare time is better for your heart health than exercise in the workplace. In fact, physically while at work Playing sports They may actually be harmful Heart healthAccording to a study published in April.

The difference in leisure and workplace exercise is a phenomenon sometimes called the “physical activity paradox,” says lead author Andreas Holtermann, PhD, of the National Research Center for Work Environment in Copenhagen, Denmark, to WebMD.

“Our findings indicate that clinicians, patients and managers should be aware that having a job that requires manual physical activity may not improve the fitness and health of workers, while physical activity should be enhanced in leisure-time health-promoting activities,” he says.

Do the exercise guidelines apply to everyone?

According to the World Health Organization and the US Department of Health and Human Services, physical activity is necessary to maintain and improve health, but these guidelines do not distinguish between leisure and work physical activity. But some research has indicated that the physical activity required at work may not provide the same benefits and may increase the risk of heart disease.

These previous studies were not robust enough to provide specific conclusions. “Much of the evidence that exists on physical activity and health is predominantly from physical activity in leisure time among the more educated white collar population,” Holterman also says. The question is whether they are progressing to an exercise while working in other groups.

To investigate the differences between manual labor and leisure time, Holtermann and his team used data from 104,046 adults (ages 20 to 100) who participated in the Copenhagen Public Population Study from 2003 to 2014. Participants came from the largest district in Copenhagen, which included the districts. High and low income.

Participants self-reported about leisure, occupational physical activity, demographic, lifestyle, medical information, and living conditions. They also performed a physical examination that included height, weight, and comfort blood pressure, And the Heart rate. Then the participants were followed for an average of 10 years.

Quantity versus quality

During the follow-up period, there were 9,846 deaths from all causes (9.5% of the participants) and 7,913 major, fatal or non-fatal heart conditions. Heart attack Or strokes (7.6% of participants).

Higher levels of leisure time activity were associated with a reduced risk of heart disease and a lower risk of death. But a lot of physical activity at work has been linked to an increased chance of heart attacks and strokes and an increased risk of death.

Holterman says the results may appear “surprising”, given the World Health Organization’s recommendation that “all steps are important in achieving better health.”

Nevertheless, he had “many years of experience” in measuring the physical activity requirements imposed on manual workers and had “extensive experience discussing this topic with employees, managers, unions, workplaces, and policymakers.”

For people who work in these environments, “it is not new that the health effects of physical activity at work differ.” But he says many “do not consider the guidelines to be appropriate for them, but for white-collar workers with higher education.”

He pointed out other differences between work practice and leisure time.

“I think the main important difference is the huge difference in dosage – often 6 to 8 hours of physical activity at work on several days in a row, compared to 30 to 60 minutes at leisure on some days of the week,” he says.

Controversial results

An accompanying editorial by Martin Hall, MD, and Melanie Heitkamp, ​​PhD, both from Technical University of Munich in Germany, object to the study’s findings.

Evidence from many populations and continents has shown broadly and consistently that regular physical activity has beneficial effects on cardiovascular health and premature mortality, a scientific finding that has been widely implemented in WHO guidelines. [World Health Organization] As well as the European Society of Cardiology.

Nevertheless, the editorial suggests some possible explanations for the “physical activity paradox” found in the current study. Leisure exercise is often more aerobic, while professional exercise may include “repetitive resistance training for short shifts and often insufficient recovery time”.

They also speculate that “workers in heavy manual labor may be particularly exposed to psychological factors (for example, night work shifts and environmental stresses such as noise or air pollution)”.

Interpret with caution

Genevieve Dunton, Ph.D., a professor in the departments of preventive medicine and psychology at the University of Southern California, also has reservations about the study’s implications, saying the findings “should be interpreted with caution.”

Although there is a “reasonable argument with assertion that professional physical activity provides fewer cardiovascular benefits than leisure physical activity … the data may not support going beyond the claim that professional physical activity in and of itself harms cardiovascular health”, as you say.

She adds that the study omits two factors that could “explain the observed correlation”, which the researchers did not take into account: emotional responses during physical activity and stress in general.

“Individuals may experience more positive emotional responses … during leisure time versus professional physical activity, which may lead to more mental health benefits and reduced risks of cardiovascular events / deaths,” she says.

She also says that those who work in manual labor suffer more psychological pressure than those who have the time and resources to practice their leisure time.

Without taking this emotional stress into account, “We need to be extremely hesitant about the claim that professional physical activity increases the risk of cardiovascular disease and death,” says Dunton.

Triple burden

Commenting on the WebMD study, Andrew Freeman, MD, co-chair of the Nutrition and Lifestyle Working Group at the American College of Cardiology, says that although physical activity – including exercise at work – is generally beneficial, “personalized physical activity Good for the heart, mind and body, and this is perhaps the most important point this study captures. “

Workplace exercises are often stressful and also linked to work responsibilities. “Exercising for a designated period -” that’s for me “- and especially being outdoors in nature, where many people walk or jog, is good for cardiovascular health, he says.

Holterman agrees, stating that physical activity at work is controlled through the production of work, while recreational exercises are tailored to personal needs, motivations and context, he says.

“People who have unhealthy manual labor are also those with fewer resources and capabilities, a triple burden that may have an important role in explaining the socio-economic gap in health,” he says.

WebMD Health News


Andreas Holtermann, Ph.D., National Research Center for Ergonomics, Copenhagen, Denmark.

World Health Organization: “World Health Organization Guidance on Physical Activity and Sedentary Behavior”.

Andrew Freeman, MD, Associate Chair, Nutrition and Lifestyle Working Group, American College of Cardiology.

Genevieve Dunton, Ph.D., Professor, Departments of Preventive Medicine and Psychology, University of Southern California.

Gamma: “Physical Activity Guidelines for Americans.”

European Heart Journal: “The Paradox of Physical Activity in Cardiovascular Diseases and All-Cause Mortality: Contemporary Copenhagen Public Study of Population with 104,466 Adults”, “Cardiovascular disease prevention: Does ‘every important step’ apply to professional work?”

© 2021 WebMD, LLC. All rights reserved.