Ryan Lochte swims blindfolded.
And, he's been doing it WAY before the "Bird Box Challenge" became a thing.
First off, DO NOT TRY THIS AT HOME -- IT'S SUPER DANGEROUS AND YOU MIGHT DIE.
But, Lochte is a pro -- surrounded by a team of coaches -- and tells TMZ Sports there's a real benefit to swimming laps with his eyes covered.
"I do that sometimes just for fun in practice. I'll swim blindfolded a couple laps just to make sure my stroke count is perfect."
Again .