Exercise does a body good, but new research suggests it does less good for obese bodies.
Swedish scientists launched a massive study to try and find out whether being highly fit can mitigate the risk of early death that comes with obesity.
Their findings, published recently in the International Journal of Epidemiology, dispel the idea that people can be "fat but fit."
In other words, weight matters.
Of the 1.3 million young men who participated in the study, the ones who were not fit but weighed a normal amount still were less likely to die over the next few decades than the fittest obese men.
The researchers focused on aerobic fitness, using a cycle test to measure their fitness levels. Obesity was defined using body mass index.
According to the World Health Organization, the higher the BMI, the greater the risk of diabetes, heart disease and some cancers.
"Low aerobic fitness in late adolescence is associated with an increased risk of early death," the authors wrote. "The risk of early death was higher in fit obese individuals than in unfit normal-weight individuals."
