What type of speed is defined as the ability to react to a stimulus in the shortest time?

Reactive speed is defined as the ability to respond to a stimulus quickly. This type of speed is crucial in many sports and physical activities where timely reactions can significantly influence performance. For example, a sprinter's ability to react to the starting gun or a soccer player's response to an unexpected pass showcases the importance of this skill. Reactive speed involves not just movement but also processing time – how fast one can perceive a situation and initiate movement in response to it.

The other types of speed mentioned do not specifically focus on the reaction to stimuli. Active speed generally refers to the speed at which an individual can move or perform within a given action, while complex speed may involve a combination of factors, including reaction time and execution of skills. Frequency speed typically relates to the rate of repetition of a movement, rather than emphasizing immediate reaction to a stimulus.