Researchers found a link between fitness during the teen years and heart attack risk down the road.
A research team looked at medical data from almost 750,000 men; they concluded those who were "fit" in late adolescence were less likely to have a heart attack 30 or 40 years later, a European Society of Cardiology news release reported.
"Our findings suggest that high aerobic fitness in late adolescence may reduce the risk of heart attack later in life. However, being very fit does not appear to fully compensate for being overweight or obese in respect to this risk. Our study suggests that it's more important not to be overweight or obese than to be fit, but that it's even better to be both fit and a normal weight," Professor Peter Nordström, of Umeå University in Sweden said in the news release.
The researchers found for every 15 percent increase in aerobic fitness the risk of heart attack (myocardial infarction or MI) in the future dropped by 18 percent.
"There were 7,575 myocardial infarctions in 620,089 men during the total follow-up time where aerobic fitness was measured, which means the cumulative incidence was about 1222 per 100,000 men," Nordström said. "There were 271,005 men (43.7 percent) who were normal weight or lean, and who had an aerobic fitness that was better than the average. Among these lean, fit men there were 2176 MIs, resulting in a cumulative incidence of about 803 MIs per 100,000 men. Thus, the cumulative incidence of MIs was reduced by about 35 [percent] in this group."
The study found a correlation between fitness and heart attack risk, but not a causal link.
"The relationship between aerobic fitness and heart disease is complex and may well be influenced by confounding factors that were not investigated in this study. For instance, some people may have a genetic predisposition to both high physical fitness and a low risk of heart disease. In a recent study of twins, we found that 78 [percent] of the variation in aerobic fitness at the time of conscription is related to genetic factors," Nordström said.
Some limits to the study include the fact that blood pressure was only taken at the time of conscription so may have changed later in life; the effect of smoking on the results was only looked at in 23,000 men; and women were not included in the study.
"As far as we know, this is the first study to investigate the links between an objective measure of physical fitness in teenagers and risk of heart attack in the general population. Further studies are needed to investigate the clinical relevance of these findings, but given the strong association that we have found, the low cost and easy accessibility of cardiovascular training, and the role of heart disease as a major cause of illness and death worldwide, these results are important with respect to public health," Nordström said.
