Swimming in a suit

Remember those full-body swimsuits that made swimmers look like they'd returned to modest Victorian times? They appeared in 2008 and immediately became very popular because of the performance enhancement they seemed to produce. They were banned from the start of 2010.

A study noted by Wired has compared swimming results with track and field results from that time period and confirmed that the suits were significant in the improved performances. Since FINA did not invalidate the records set with the suits it's probably going to be some time before their blemish is removed from the record books...