Mark Wahlberg and Rhea Durham are living proof ... fitness is not a young person's game.
Not that they're old, but their bodies simply defy age ... paste the heads of a couple 20 year olds over them and you'd never know Mark is 52 and Rhea is 45.
Mark and Rhea have been vacationing in Barbados, along with tons of other celebs.
They have 4 kids together, who came along for the vacay.
Rhea joked about the brood they brought along ... "What do 4 teenagers,1 college kid and one family friend have in common? A free vacation."
They know how to live, that's for sure.