Although Harper has just a master's degree, she is helping spearhead several studies documenting how the physiology and performance of transgender athletes change as they make their transition. That work helped make Harper an unpaid adviser for sporting bodies, such as the International Olympic Committee (IOC), that are wrestling with transgender issues and other matters of gender. Although Harper's study included only a few transgender women, Eric Vilain of The George Washington University in Washington, D.C., a geneticist who specializes in gender-based biology, calls it 'groundbreaking.' In 2015, she published the first study of transgender athletes' performances, finding that transgender women who received treatment to lower their testosterone levels did no better in a variety of races against female peers than they had previously done against male runners. But Harper, a medical physicist at a large medical center in Portland, Oregon, has been challenging that assumption with data. Many people believe transgender women such as Harper have athletic advantages over non-transgender women-sometimes called cisgender women-because of their previous exposure to male levels of testosterone. But this division of the sexes, which has existed for as long as women have competed as athletes, forces an important question: Who, at least from an athletic standpoint, is female? Sporting events are therefore usually split into male and female categories to ensure fair competition.

That hormone-fueled transformation confers certain athletic advantages, and men on average run faster, lift more weight, and throw harder and farther than women. The testosterone that courses through a man's body after puberty triggers and maintains a slew of physical changes: Men, whose levels of the hormone are usually some 10 to 15 times those of women, typically have larger muscles, denser bones, and higher fractions of lean body mass than women. Harper's timing was deliberate-the 47-year-old nationally ranked runner wanted one more race before disrupting her hormones because she knew she'd never run as fast again. They delivered a small dose of estrogen and a testosterone blocker and set in motion changes that Harper, who was designated male at birth and raised as a boy, had imagined since childhood. PORTLAND, OREGON, AND PHOENIX-Joanna Harper swallowed a few pills in late August 2004, a day after running in the Hood to Coast relay race between Oregon's highest mountain and the Pacific Ocean.

Man transform into a woman