If you were, or are, out of shape at age 18, you may be at risk for developing Type 2 diabetes, regardless of your weight and family history, a new study suggests.

The study looked tracked 1.5 million Swedish men, using tests of muscle strength and aerobic capacity at age 18, between 1969 and 1997. The researchers then checked the men’s medical records from 1987 to 2012 and found 34,008 cases of diabetes over an average 26 years of follow-up, The New York Times reports.

The results, published in the Annals of Internal Medicine, found those with both low aerobic capacity and low muscle strength at 18 were far more likely to develop for Type 2 diabetes later in life.

The link held true regardless of other risk factors, such as body mass index, family history of diabetes, education, and socioeconomic status.

“Early life interventions are really important,” said lead researcher Dr. Casey Crump, a professor of family medicine at the Icahn School of Medicine at Mount Sinai in New York. “Prevention of Type 2 diabetes should begin early in life, and should include both aerobic fitness and muscular strength. This is important regardless of people’s weight.”