Quoting thats me:
"hey i read somewhere (although i don't remember where) on the web that synchronized swimmers have their feet tickled in order to better their concentration."
Probably where you read it was here, on the Stories forum. Unfortunately, it's not true.
One of my cousins was a synchronized swimmer in HS and college. She and one of her girlfriends went "pro" and took a summer jobs (they're schoolteachers) as synchronized swimmers at the World's Fair in New Orleans about 1985. I assure you, when I tickled their feet, it didn't "better their concentration" - actually, just the opposite - nor did I intend it as such.
But it was a lot of fun.
Strelnikov