Women are naturally fitter than men. A new study published in the journal Applied Physiology, Nutrition and Metabolism looked at the natural fitness ability of women as compared to men. Researchers from the University of Waterloo directed women and men who were of a similar age and BMI to walk at gradually increasing speeds and inclines on a treadmill, going until they had reached 80% of their maximum heart rate. Each person wore a face mask to measure how much oxygen they used and how much carbon dioxide they produced.The results found that women adjusted to the exercise after about 30 seconds, while men took 42 seconds. Women had a 30% faster rate of processing oxygen overall, a clear advantage when it comes to physical efficiency. It’s important to remember that fitness can’t just be defined by aerobic power; how quickly a person adapts to an exercise level is really a good indicator of health and fitness.