According to a new study published in the journal Applied Physiology, Nutrition, and Metabolism, women can process oxygen more quickly than men when they start to exercise.

Quick oxygen uptake places less strain on the body’s cells and is considered an important measure of aerobic fitness.

“Previous studies in children and older adults demonstrated faster oxygen uptake kinetics in males compared with females, but young healthy adults have not been studied,” said lead author Dr. Thomas Beltrame from the University of Waterloo and co-authors.

“We hypothesized that young men would have faster aerobic system dynamics in response to the onset of exercise than women.”

The researchers compared oxygen uptake and muscle oxygen extraction between 18 young men and women of similar age and weight.

“Eighteen healthy active young women and men (9 of each sex) with similar aerobic fitness levels volunteered for this study,” they explained.

“Participants performed an incremental cardiopulmonary treadmill exercise test and three moderate-intensity treadmill exercise tests.”

Women consistently outperformed men with around 30% faster oxygen handling throughout the body.

“The findings are contrary to the popular assumption that men’s bodies are more naturally athletic,” Dr. Beltrame noted.

“We found that women’s muscles extract oxygen from the blood faster, which, scientifically speaking, indicates a superior aerobic system,” added co-author Professor Richard Hughson, also from the University of Waterloo.

“By processing oxygen faster, women are less likely to accumulate molecules linked with muscle fatigue, effort perception and poor athletic performance.”

“While we don’t know why women have faster oxygen uptake, this study shakes up conventional wisdom,” Dr. Beltrame said.

“It could change the way we approach assessment and athletic training down the road.”

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Thomas Beltrame et al. 2017. Sex differences in the oxygen delivery, extraction, and uptake during moderate-walking exercise transition. Applied Physiology, Nutrition, and Metabolism 42 (9): 994-1000; doi: 10.1139/apnm-2017-0097