On Monday, it ended its requirement that soldiers do at least one leg tuck — where they hang from a bar and pull their knees up near their shoulders — as part of the new physical fitness test, as it became clear that many troops — particularly women — were unable to do it. Now, soldiers will have the option of choosing another exercise called the plank, that also shows core strength.

That new option is just one of the changes Army leaders are making in their struggle to create a fitness test that is gender neutral, but that also doesn't end up disadvantaging female soldiers who simply aren't as strong as their male counterparts.

In a sweeping nod to gender differences, Army leaders said Monday they are also going to create a new tiered system that will mask some of the fitness score differences between men and women when it comes to promotions or other job selections.