The F.B.I.’s 13,500 agents worldwide have until October to take it and the results will be included on their annual performance reviews. The test is primarily designed to ensure that agents can move quickly during a mass shooting, chase suspects and restrain them if they resist arrest. There are no weight limits, but agents have to achieve certain requirements in four different exercises depending on their age and gender. The threshold to pass is not nearly as high as it is for military commandos or hostage rescue-team members.

For instance, male agents ages 30 to 39 must perform 24 push-ups without stopping and 35 situps in a minute. They have to sprint 300 meters in less than a minute and run a mile and a half in 12 minutes and 53 seconds.

The most challenging part of the test, agents said, is that they get only a five-minute break between exercises. Men are typically better at the push-ups than situps, but it is the reverse for women. Everyone struggles with the sprint.

So far, there has not been a stampede to take the test, including at the Washington office, where only 75 of 800 agents have subjected themselves to it (all passed). Although the F.B.I. has never had the kind of fitness culture of, say, the Marines, the agents are competitive, and many who have put off the test are working for higher scores.

“It’s really not that hard,” said Jennifer Schick, a public corruption agent at the F.B.I.’s Washington field office who also oversees fitness training and tests. “Most agents wouldn’t be satisfied in just coming out and making the minimum. They would be embarrassed by that, and that is why they’re waiting.”

To help them prepare, the F.B.I. is offering training sessions like one on the National Mall at sunrise on Friday, when Ms. Schick stood over a dozen agents who did push-ups until their bodies collapsed to the ground in exhaustion. They did lunges to build leg strength and ran wind sprints. “Unfortunately, some people told me they are embarrassed to come and show other people how out of shape they are, and that’s a shame because they are the ones who really need it,” Ms. Schick said.