For decades, the blueprint for endurance success—the intervals, the tapering strategies, and the fueling protocols—has been built on a foundation of data derived almost exclusively from men. If you are a female runner, cyclist, or triathlete, there is a high statistical probability that the training plan you are following was designed for a body that doesn't share your hormonal profile or physiological baseline.

The immediate differences that distinguishes female athletes from male athletes is usually focused on the body size and organ...