Firefighting causes stiff arteries

CHAMPAIGN, Ill., Aug. 12 (UPI) -- Fighting fires causes stiff arteries and "cardiac fatigue," a condition also found in weightlifters and endurance athletes, U.S. researchers say.

Bo Fernhall, a professor at the University of Illinois College of Applied Health Sciences, and Gavin Horn, the director of research at Illinois Fire Service Institute at the University of Illinois, said firefighters do a lot of resistance-type exercise when they're fighting a fire -- handling heavy equipment, doing forcible entry and other tasks that increase blood flow in their arms, which is where endothelial functioning is measured.

The 69 firefighters -- all male with an average age of 29 -- who participated in the study were in active service and had been medically cleared by their home departments to participate in live-fire activities. However, many were overweight, as assessed by body mass index.

Wearing full firefighting gear, the participants engaged in typical fire suppression activities -- advancing hose, forcing doors open, extinguishing a fire -- for four or five activity periods of 15-25 minutes each, with several 10-15 minute rest periods.

The study, published in the journal Vascular Medicine, found just 3 hours of firefighting activity caused acute increases in arterial stiffness and impaired cardiac functioning in young, apparently healthy male firefighters.

"The arterial stiffening is not a response that we would expect," Fernhall says in a statement. "Whether the results increase the risk of a firefighter having a heart attack or stroke, we don't know."