A national necropsy survey was conducted to examine the relationship between physical activity of work and coronary heart disease in middle-aged men. The study analyzed 3,800 non-coronary deaths and found that men in physically active jobs had a lower incidence of ischaemic myocardial fibrosis compared to those in sedentary or light jobs. This fibrosis, often a sign of early coronary heart disease, was more prevalent in light workers, with 13.4% compared to 6.8% in heavy workers. Large fibrous patches, indicative of major infarctions, showed a stronger association with physical activity, with threefold differences between light and heavy workers. The findings suggest that physical activity may reduce the severity of coronary heart disease, though the exact mechanisms remain unclear. The study also found that hypertension was more common in light workers and was associated with a higher prevalence of smaller, multiple scars. The results indicate that physical activity may protect against coronary heart disease, but further research is needed to confirm these findings and explore the underlying mechanisms. The study highlights the importance of considering occupational physical activity in understanding coronary heart disease and its prevention.A national necropsy survey was conducted to examine the relationship between physical activity of work and coronary heart disease in middle-aged men. The study analyzed 3,800 non-coronary deaths and found that men in physically active jobs had a lower incidence of ischaemic myocardial fibrosis compared to those in sedentary or light jobs. This fibrosis, often a sign of early coronary heart disease, was more prevalent in light workers, with 13.4% compared to 6.8% in heavy workers. Large fibrous patches, indicative of major infarctions, showed a stronger association with physical activity, with threefold differences between light and heavy workers. The findings suggest that physical activity may reduce the severity of coronary heart disease, though the exact mechanisms remain unclear. The study also found that hypertension was more common in light workers and was associated with a higher prevalence of smaller, multiple scars. The results indicate that physical activity may protect against coronary heart disease, but further research is needed to confirm these findings and explore the underlying mechanisms. The study highlights the importance of considering occupational physical activity in understanding coronary heart disease and its prevention.