[9YearLurker]

Pullups are very, very hard for women: their arm strength to lower body weight is almost always off.

[circlecity]

"Pullups are very, very hard for women: their arm strength to lower body weight is almost always off."

Although the arms are certainly involved a pull up primarily engages the back muscles, particularly the latissimus dorsi. (your "lats") They are the muscles that give the upper body that "V" shape when viewed from behind.