The speed of a body at a given moment in time. It is estimated as the average speed of a body over such a very short distance or such a very short period of time (starting from the position the body is in at the instant in question) that the speed will not have time to change. It can be determined by the gradient of a distance/time curve. A car's speedometer measures instantaneous speed. The concept of instantaneous speed is useful when comparing different periods of performance, such as the different stages of a sprint.
Subjects: Sports and Exercise Medicine.