Brandon Marshall -- My Wife Just Had Twins ... And She's Already Pre-Baby Weight!

Brandon Marshall is a dad ... TIMES TWO ... 'cause his wife Michi just gave birth to twins last month -- and the NFL star says she's already bounced back to her pre-baby weight!

The Chicago Bears wide receiver says the kids just celebrated their 6 week birthday -- and just like Wladimir Klitschko, he's super impressed with his bad ass wife.

"My beautiful wife is not from this planet," Marshall says ... "6 weeks post baby (×2) and she's already at her pre baby (×2) weight. Her discipline with her diet and mutant genes has her #snapback game #CRAZY."

Congrats!