Mark Wahlberg Posts Shirtless Pic of His Impressive Physique After 6 Months of Training and Clean Eating

Mark Wahlberg is proudly showing off his hard work.

Mark Wahlberg is proudly showing off his hard work.

The 48-year-old actor shared a shirtless picture of himself flexing on Instagram on Thursday, displaying his defined biceps and chiseled abs. The father of four said he's been eating clean and doing F45 training -- a global fitness community specializing in high-intensity group workouts -- for six months.

"Six months of Performance Inspired Nutrition, Aquahydrate, and F45 training!!" he wrote. "Clean eating. Inspired to be better, team training / life changing. ?❤️? @performinspired @aquahydrate @f45_training."

Wahlberg is of course known for his dedication to fitness, previously sharing that he works out at 4 a.m., often gets in two workouts a day and uses a cryo chamber that dips down to 150 degrees below zero to help his muscles after a workout.

He frequently posts videos of himself exercising, including a recent one with his 11-year-old son, Brendan.

Last October, Wahlberg told ET that his Instant Family co-star, 47-year-old Octavia Spencer, joined his 4 a.m. workout club while filming the movie.

"I got phone calls from some of like, the biggest stars in town, like, 'I'm coming to the 4 a.m. club. I aspire to be better.' Nobody showed up," he recalled. "She comes in and she kills it. You know what? She's inspiring so many other people."

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