One of the key measures of aerobic fitness lies in how quickly the body is able to draw oxygen from the blood. While previous studies suggest that males generally outperform females when it comes to children and older adults, a new study indicates that younger women consistently outdo younger men.

Led by researcher Thomas Beltrame of Canada's University of Waterloo, a team of scientists compared oxygen uptake and muscle oxygen extraction (how quickly the muscles extract oxygen from the bloodstream) between 18 young men and women of similar age and weight during treadmill exercise.

In all cases, the nine women exhibited about 30 percent faster oxygen handling throughout the body. This means that they were less likely than the men to accumulate molecules that are linked with muscle fatigue and poor athletic performance.

"The findings are contrary to the popular assumption that men's bodies are more naturally athletic," says Beltrame. "While we don't know why women have faster oxygen uptake, this study shakes up conventional wisdom. It could change the way we approach assessment and athletic training down the road."

A paper on the research was recently published in the journal Applied Physiology, Nutrition, and Metabolism.