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Numerous studies substantiate the immense benefits of an active lifestyle. Regular exercising reduces the risk of respiratory illnesses like colds, flu, and COVID-19, along with the risk of subsequent complications. At the same time, scientists have suspected that excessive activity, especially prolonged and high-intensity, can also elevate susceptibility to diseases.
Researchers from the Pacific Northwest National Laboratory, conducting studies in the realm of national security, collaborated with colleagues from other institutions to assess the impact of intensive activity on the bodies of individuals whose professions involve excessive physical demands. This primarily pertains to military personnel, firefighters, police officers, and professional athletes.
About the Study
A research, though small in scale, sheds light on a potential mechanism. Researchers examined the blood, saliva, and urine of 11 firefighters before and 10 minutes after intense exercises designed to mimic wildfire fighting. The firefighters hiked over hilly terrain for 45 minutes in humid weather wearing up to 44 pounds of wildland gear.
Heavy Loads Affect Our Immunity
Post-exercise, participants exhibited lower levels of proinflammatory cytokines and ceramides and higher levels of antimicrobial peptides. These changes indicate increased susceptibility to infection, according to the researchers. A systematic review also identified several studies involving marathon runners, firefighters, soldiers, and football players, revealing heightened respiratory symptoms after strenuous workouts.
Antimicrobial peptides are part of the immune response, but they’re usually not very effective for viral infections. That’s why we think it may make you more exposed to respiratory infections.
Lead author Ernesto Nakayasu, PhD, senior research scientist at the Pacific Northwest National Laboratory, a US Department of Energy lab in Richland, Washington
According to Dr. Nakayasu, additional research is needed to determine the duration and intensity of exercise required to induce these immune changes.
Furthermore, during intense physical activities, individuals typically breathe through their mouths, bypassing nasal barriers. This allows more microbes and viruses to penetrate and settle in the respiratory pathways.
Medical Advice to Guard Against Colds
Maintain a moderate exercise routine and ensure adequate rest and recovery after intense workouts. For individuals engaged in strenuous and prolonged physical activity, experts recommend getting vaccinated against COVID-19 and seasonal viral infections.
Experts caution that we are entering another potential tripledemic this winter. An increase in cases of COVID infection, the flu, and respiratory syncytial virus (RSV) is anticipated. Due to the heightened flu activity in Australia this year, health authorities are concerned about the potential severity of the upcoming flu season.
