These well-rehearsed motor patterns which we can call on without much thought are called engrams by psychologists. Research by Franklin Henry at the University of California revealed that we do not necessarily possess general speed, but may possess specific speed. In other words, there is little if any carry-over from one sport to another unless the skills are nearly identical. If we pick ten school children of the same age and ask them to sprint 100m flat out three times with adequate rest after each effort, the odds are that the first three places will be filled by the same athletes. But, if the distance were then shortened to 60m the result may differ a little owing to some having a faster reaction time to the gun and possibly better starting technique.
Speed is defined as rate of stride multiplied by length of stride.
The first three home in the 100 yards dash may have different speed abilities. One might have a rate of five strides a second and cover 2m per stride, making a total distance of 10m covered in a second. But another may only have a rate of four strides a second and cover 2.6m per stride, resulting in 10.4m being covered in a second, slightly faster than the faster striding runner. While the rapid strider may have more fast-twitch muscle fibres in his legs, the slower strider may be able to exert more force on the ground as his foot pushes off to cover more distance. This latter point is a pungent answer to those who believe that sprinting speed cannot be improved and that we are either born fast or slow.