Reaction Time

Reaction Time in swimming is the interval between the starter’s signal (such as a gun or beep) and the moment a swimmer’s feet leave the blocks. It indicates how powerful and concentrated an athlete is at the beginning. Modern timing systems record reaction times using pressure sensors on the starting blocks—typically less than 0.7 seconds for elite swimmers. In relays, the reaction time for the second through fourth legs is taken from the moment the incoming swimmer touches the wall until the next swimmer leaves the block. This ensures the changeover occurs at the correct time and monitors for early takeoffs.