Tim McGraw on Tuesday showed he’s not country strong, he has an impressive physique.

The country star took to Instagram to show off his first-ever yellowfin grouper, which the 52-year-old singer revealed, he caught with a pole spear while free diving 36 feet underwater.

"Yellow fin grouper 1st one! 36 ft down Pole spear ... free dive," he captioned the snap.

In the pic, a shirtless McGraw -- wearing only a pair of neon orange swimming trunks and a blue cap -- is seen holding up his prized catch and while, some fans noticed the yellow grouper, many couldn't help but point out McGraw's chiseled abs.

McGraw has long been known for his strict diet and, according to The New York Times, his “grueling workout.” In 2015, the 52-year-old told the paper he toured with a portable gym that includes free weights, 20-pound chains and other equipment. His workouts start with runs up hills with 40-pound weights strapped to his ankles.

The paper reported that he does a combination of CrossFit and martial arts.

Diet also plays a major role in McGraw’s routine and tries to be strict for three or four days a week. The paper reported that he’ll eat oatmeal with berries for breakfast, a protein shake for a midmorning snack and tuna with avocado for lunch. For dinner, it’ll be a grilled chicken breast with a vegetable and polenta. Oh, and no alcohol. He has since lost 40 pounds, but he said losing weight was not his objective.

He recently told Country Living that 10 years ago, he was not taking care of himself.

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"My lifestyle wasn’t as good: up until 3 o’clock in the morning, having that extra beer with the band, eating cheeseburgers late, and not hitting the gym in the morning," he said. He said he was inspired by his daughter, who told him he had to do something after seeing him in the movie “Four Christmases.”

He said he was in the gym “the next day.”

Fox News' Mariah Hass contributed to this report