To find out just how meaningful a fitness measure the pull-up really is, exercise researchers from the University of Dayton found 17 normal-weight women who could not do a single overhand pull-up. Three days a week for three months, the women focused on exercises that would strengthen the biceps and the latissimus dorsi — the large back muscle that is activated during the exercise. They lifted weights and used an incline to practice a modified pull-up, raising themselves up to a bar, over and over, in hopes of strengthening the muscles they would use to perform the real thing. They also focused on aerobic training to lower body fat.
By the end of the training program, the women had increased their upper-body strength by 36 percent and lowered their body fat by 2 percent. But on test day, the researchers were stunned when only 4 of the 17 women succeeded in performing a single pull-up.