A study in Medicine & Science in Sports & Exercise looked at different levels of physical activity and their effect on the incidence of bacterial infection. It was found that low and moderate physical activity had a statistically significant impact on lowering the risk of filling an antibacterial prescription compared with remaining sedentary. These findings add to the knowledge of exercise and immunology.
Physical activity affects the immune system, and there is much evidence that low and moderate physical activity reduces the severity and incidence of viral infections.
Bacterial infections are a considerable cause of mortality worldwide, and they place a burden on the health care system and on society. Although much research has gone towards the relationship between physical activity and viral infection, and despite the effect bacterial infection has on the health care system, little research has gone into the relationship between physical activity and bacterial infection. This study focused on different levels of physical activity and their effects on incidence of bacterial infection.
The study was based on residents who completed the North Denmark Region Health Survey, originally aimed at compiling information on the general health of citizens of the North Denmark Region. Health surveys were sent out to citizens at two different time periods, either from November 2006 to February 2007, or from February to March 2010. 18, 847 participants made it into the final study, after removing those with chronic diseases as to not bias the results. Assessment of physical activity was on a 4 level scale of vigorous physical activity, moderate physical activity, low physical activity, and sedentary behaviour. Instance of bacterial infection was based on filled antibiotic prescriptions, which were retrieved from the Danish National Prescriptions Registry.
Overall, researchers found that compared with sedentary behaviour, low and moderate physical activity was statistically significant in lowering the risk of filling an antibiotic prescription by 10%, while vigorous physical activity was not. The results differed slightly between men and women. In men, it was suggested that while low and moderate levels of physical activity lowered the risk of filling an antibiotic prescription, vigorous physical activity actually increased the risk, although none of the results were statistically significant. In contrast, in women it was suggested that all types of physical activity lowered the risk of filling an antibiotic prescription, while the association to vigorous physical activity was found not to be statistically significant.
The results of this study are important because it adds knowledge to the area of exercise and immunology. It was shown that there is a significant protective effect of low physical activity on developing bacterial infection in comparison to remaining sedentary.
While this study had its strengths in its utilization of national registries, it also had its limitations. It is possible that doctors misdiagnosed when prescribing antibiotics, and not all people with a bacterial infection are prescribed antibiotics. In addition, the question used to measure a participant’s level of physical activity was very simplified.
Written By: Samantha Guy, BSc