Happy birthday Tim McGraw!

The country star turns 48 today, but it really feels like our birthday, seeing as the singer/actor just treated us all to a shirtless workout in San Diego, Calif. Check out Tim working hard on his fitness outdoors in the heat on Thursday, no gym needed.

Watch out Zac Efron -- looks like Tim might have the best abs in Hollywood.

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Obviously, the Tomorrowland actor's amazing eight-pack doesn't come without tons of hard work. He recently told the New York Daily News that he makes sure to mix it up with Crossfit, running, and weight lifting.

"I'll be the first to admit I take it to extremes," he told Men's Health last June about his workouts. "I'm not one of those people who can sorta half-ass something."

Tim eats pretty healthy too.

"It's almost anti-country singers, but one of my favorite things is a kale salad (with) all kinds of things in it: walnuts, pumpkin seeds, parmesan cheese, olive oil, lemon," he told the New York Daily News.

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Tim and his wife Faith Hill attended the Time 100 Gala earlier this month, where they brought along their stunning teenage daughters Gracie, 17, Maggie, 16, and Audrey, 13. Check out the adorable family in the video below!