WASHINGTON — The Army is kicking out the leg tuck.

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, which 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 and age neutral, but that also doesn’t end up disadvantaging female or older soldiers who simply aren’t as strong as their younger male counterparts.

In a sweeping nod to gender differences, Army leaders said Monday that 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.

Under that system, soldiers will take the fitness test, which includes six exercise events. The minimum score for passing is 60 points on each event, for a total of 360, and the maximum is 100 points for each event, for a total of 600.

Soldiers will be assigned a ranking based on how they did compared to others of the same gender. For example, if they score in the top 1% of their gender, they are in the platinum category, or if they are in the top 10% of their gender, they are in the gold group. That ranking category would then show up on internal reports for promotions or other competitive assignments where a higher physical fitness score could be a deciding factor.

The new tiered system, said Maj. Gen. Lonnie Hibbard, “fosters and recognizes above-average physical performance, something that’s inherent to the Army culture. And second, it accounts for the recognized physiological differences between men and women, and it removes the direct competition between males and females within the service.”

For years, Army leaders have been wrestling with how to change the physical fitness test to better reflect combat requirements and improve the overall fitness of the force. After much study, they jettisoned the longtime test of situps, pushups and a 2-mile run, and developed a more grueling fitness exam designed to make soldiers more fit.

As they started to roll out the new test, they knew that adjustments would have to be made. The leg tuck, said Hibbard, was the “No. 1 failed event for both men and women,” as well as for older soldiers.

“As you look at those service members who have been in the Army, especially 15, 20 years and have never been asked to build the upper body strength necessary to do a pullup or do a leg tuck, it gets significantly harder as they get older to build that strength,” said Hibbard, commander of the Army’s Center for Initial Military Training.