Teen fitness may protect against later heart disease, study indicates

The scientists looked at data on 8,986 male adolescents, most of them Swedish military conscripts, taken when they were about 18 and again nearly 40 years later. The subjects, all under age 20 at conscription, were initially assessed for cardiovascular fitness and tested for upper-leg strength.

Decades later, a final sample of middle-aged subjects was tested for the amount of plaque in their coronary arteries using noninvasive coronary computed tomography angiography. According to the National Institutes of Health, atherosclerosis, the primary pathway for the development of cardiovascular disease, develops when a substance called plaque — formed from cholesterol, fat, blood cells and other substances — builds up in the arteries, causing stenosis, or narrowing.

Disease linked to atherosclerosis is the leading cause of death in the United States, NIH says. The study, which the researchers say is the first to examine physical fitness in early life and the development of coronary atherosclerosis in middle age, points to the importance of cardiovascular exercise not only for heart health but also for muscle strength. The combination of the two provided the most benefit in the study, the researchers said.

“Although further well-designed studies are needed, our findings suggest that adequate physical fitness already in adolescence may reduce coronary atherosclerosis later in life,” the researchers wrote. Swedish military conscription was mandatory only for men before 2010, and the researchers acknowledged that the study does little to explain how fitness influences cardiovascular disease risk in women.