Fitness Testing
Obviously, FBI agents have to be physically fit. They need to be able to be on their feet all day. At times, they're going to need to use some brute strength, so everyone has to be in tip-top condition.
To become an agent, they must pass a physical evaluation before they could even consider getting hired. They have to do sit-ups, a timed 300-meter sprint, continuous push-ups, and a timed 1.5-mile run. All of these have to be performed back to back, with no breaks in between.