Which of the following is NOT one of the five components of fitness?

The five components of fitness are essential areas that contribute to overall physical health and athletic performance. These components include muscular strength, body composition, cardiovascular endurance, flexibility, and muscular endurance.

Reaction time is not classified as one of these five primary components. While reaction time is indeed a crucial aspect of physical performance—especially in sports contexts where quick responses are necessary—it does not fit into the main categories that define physical fitness. The other components focus on areas such as strength, endurance, and the physical makeup of the body, all of which are measurable and directly linked to an individual's fitness level. Thus, identifying reaction time as outside this foundational list highlights an important distinction in fitness education.