Which muscle group does the sit-up test primarily measure the endurance of?

The sit-up test primarily measures the endurance of the rectus abdominis and the external obliques because these muscle groups are heavily recruited during the flexion of the spine that occurs in a sit-up. The rectus abdominis is the primary muscle responsible for bringing the torso forward from a supine position, while the external obliques assist with this motion and also play a role in rotation and lateral flexion of the trunk.

When performing sit-ups, the individual uses these muscles in a repetitive manner, which is essential for assessing muscular endurance. The ability to perform multiple repetitions indicates how well these muscles can maintain contraction over time, reflecting their endurance capabilities. Other muscle groups mentioned, such as the hip flexors or muscles of the upper back like the latissimus dorsi and trapezius, are not the primary focus in this exercise, making them less relevant for measuring endurance in the context of a sit-up test.