Mark Wahlberg showed off his rock hard ... who “haven’t worked out in a long time.” For more Page Six you love… In pure Wahlberg style, he finishes off the strenuous session with a cold ...

Before Mark Wahlberg’s wife ... he walked towards the camera, sporting his six-pack and chiseled arms. “4 a.m., rain or shine,” he said to the camera. “It’s raining outside.

Fitness doesn't take a holiday in Mark Wahlberg's house ... a locker-room shower wearing a pair of navy-blue shorts, his six-pack abs front and center. "Nothing like a cold plunge in the rain.