Type 2 diabetes is a difficult disease to manage that increases the risks of kidney failure, heart disease and blindness. Over 300 million people globally are affected.
Becoming overweight or obese are well established risk factors for developing diabetes. Another risk is physical inactivity. What is less understood, is whether being fit has the opposite effect and is protective.
Physical fitness can be measured as both aerobic capacity and strength. These were measured in 1 547 478 men conscripted into the Swedish military service at age 18, between 1969 and 1997.
Only young men who were incarcerated or who had diagnosed chronic diseases or disabilities were excluded. Aerobic capacity and strength was classified as low, medium or high. Incidence of diabetes in the men was recorded.
In the years after these fitness tests, those who had low aerobic fitness or low strength were more than twice as likely to develop diabetes as the men who were either fit or strong. If the men were both unfit (low aerobic capacity) and weak (low strength), the risks of diabetes increased by at least three times.
Implications
This study highlights just how important being fit and strong is in protecting against a serious disease like diabetes. There are many questions unanswered by this study, including what happens to the fitness and strength of the men as they get older.
Almost everyone loses fitness and strength, yet those people who regularly exercise stay ahead of people their own age who are sedentary. Being fit has many benefits, including improving mental health. Protecting against diabetes is one very important health benefit.
