Why are the times of relay swimmers 2-4 often faster than the world record times?

Question

Most people that have followed the Olympic swimming events in Beijing have most likely seen the 4x100m freestyle relay that the US surprisingly won ahead of France. Jason Lezak posted a low 46 seconds time. Many other relay swimmers swimming in position 2 thru 4 posted faster times than the current world record. I am puzzled by this. I would think that the judges closely watch whether an athlete jumps into the pool prior to his team mate touching the wall. In any case, even a slight discrepancy there does not explain 1 second differences in the times posted. Can somebody shed light on this?

Thanks!

Answer 1

This is due to the fact that they can anticipate the start.  They follow the swimmer in and and are in motion prior to the touch.  They only need to not leave the blocks before the touch to be legal.  The lead swimmer can not move at all until the gun goes off.

Answer 2

Ok relays give you a ton of adrenaline especially in that one. Plus you tend to have a better reaction time and it is for your team mates and not just you. I always swim faster in relays. Jason caught a wave that gave him an advantage and he was more pumped than anything.