Billie Jean King is about 80 years old and played tennis against a man...she never ran or did anything else with men that would have caused her to be handicapped/penalized by her smaller or weaker body...
What do young females, teenagers and in their 20s have to say about men competing against them in sports such as running etc ???
Most road races, from 5k to the Marathon, have men and women running the same course together. When I was a semi-serious runner one of my goals was to beat or finish near the top women. They usually finished in the top 10% of the field, so I was guaranteed a respectable finish. Sometimes they'd even push or pull me to an age group trophy!