Fitness in Teen Years May Guard Against This
Swedish study found link between aerobic fitness at 18 and lowered heart attack risk in middle age
By Dennis Thompson
WEDNESDAY, Jan. 8, 2014 (HealthDay News) -- People who are aerobically fit as teenagers are less likely to have a heart attack in middle age, a study of nearly 750,000 Swedish men suggests.
Every 15 percent increase in aerobic fitness in your teen years is associated with an 18 percent reduced risk of heart attack three decades later, researchers report in the Jan. 8 online edition of the European Heart Journal.
The results also suggest that teens and young adults who undergo regular cardiovascular training have a 35 percent reduced risk of heart attack later in life.
Aerobic fitness as a teen even appears to help people who become obese later in life, said research leader Peter Nordstrom, of Umea University in Sweden.
"It should be noted that aerobic fitness decreased the risk of heart attack significantly within also overweight and obese men," Nordstrom said. Obese men who had the highest aerobic fitness as teens enjoyed a 60 percent lower risk of heart attack compared with obese men who had the least fitness.
However, obese men with high aerobic fitness did have a higher risk of heart attack than lean men with little aerobic fitness. While the study found an association between aerobic fitness and chances of heart trouble, it did not establish a cause-and-effect relationship.
The findings emphasize the need for improved physical fitness among young people, said Dr. Stephen Daniels, chairman of pediatrics at the University of Colorado School of Medicine and a spokesman for the American Heart Association.
"Even though the diseases we see are diseases of older adults, it's increasingly clear that where people are in childhood and adolescence is critically important," Daniels said. "We probably aren't doing enough to help our young population become fit and avoid obesity."
For the study, the researchers analyzed medical data from 743,498 men drafted into the Swedish army at age 18 between 1969 and 1984.
As a part of induction, all of the draftees took part in a physical examination that included a test of their aerobic fitness. They all had to ride on an exercise bicycle until they were too exhausted to continue.
National health registers provided information on heart attacks the men suffered later in life. Doctors used this medical data to track men for an average 34 years following their military physical exam.
The researchers found that men with the lowest aerobic fitness had a more than twofold increased risk of later heart attack compared with men who were most fit.
The study authors also looked into the joint effect of obesity and fitness, and found that across all weight groups the risk of a later heart attack increased significantly when comparing the least fit with the most fit.