Mark Wahlberg Accepts Dr. Oz Push-Up Challenge with a Twist

Someone's leaving in an ambulance, and Mark Wahlberg is positive it'll be Dr. Oz ... IF the good doc follows through with his push-up challenge ... to settle the great breakfast debate once and for all.

It all started out kinda funny, but Mark's no longer laughing, saying to Oz, "We got beef now. You don't want this smoke" -- making it clear he's down for whatever physical competition Oz wants.

You'll recall ... Oz threw down the gauntlet earlier this week when he told us he'd crush Marky Mark in a one-legged push-up contest ... all because Mark disagreed with Oz's controversial break-xit remark -- that we should do away with breakfast altogether!!

Careful what you ask for, Oz, 'cause Mark's dead serious -- "You could do your little 20 push-ups with one leg, your assisted pull-up. I'm telling you you'll need a defibrillator when I'm done with you!"

He'll even give Oz a head-start of sorts ... a booze and food handicap!!! You just gotta watch. Mark's so pumped, he even talks trash to his friend Dr. Christopher Vincent, who -- shocker -- sounds like he's siding with Dr. Oz.

So, here's the thing -- this all started with these guys talking to TMZ, so we're offering to end it. Our doors are open to both you push-up gladiators! Mark and Oz, come on down to our office ANYTIME to settle the beef.

And, yeah ... we got defibrillators.