Tim McGraw shares how he dropped 40 pounds and got in the best shape of his life

Tim McGraw is opening up about how he adopted a new active lifestyle and lose 40 pounds.

In the latest issue of Men's Health, the 52-year-old country music star explains that it was a frank conversation with his now-22-year-old daughter, Gracie, in 2008 that offered him perspective and inspired him to get active.

After the release of McGraw's film, Four Christmases, Gracie mentioned to him that he looked "big on the screen." That moment stuck with McGraw, who tells the magazine, "I got out of it for a while. I was in the prime of my career and I wasn't capitalizing on it."

So, the singer started to cut out burgers and alcohol, as well as "truck-stop foods" and began starting his days with a morning walk. Pretty soon, he was going on 20-minute runs and lifting weights. McGraw began to notice that all this hard work and dedication in the gym was translating to his performances on stage.

"I use my whole body to sing -- my legs, my butt," he says. "And having more control over those things makes my voice stronger."

Now, 11 years after choosing to change his lifestyle, McGraw has transformed and takes pride in the hard work that got him there -- even launching a wellness brand, TRUMAV. And this month, he's released a health and fitness book, Grit & Grace: Train the Mind, Train the Body, Own Your Life.

"Most things in this business are out of your control. What the radio is going to play, how many records you're going to sell. Control the things you can, and maybe that helps," he shares. "This workout is my meditation. It frees things up in your head so you can get the trash out for a little while."

Earlier this week, McGraw posted a photo of himself in the gym along with an inspiring message for fans: "My whole life, I've lived according to one key value. I guess I've done so from an early age, when I wanted so fiercely to get beyond my circumstances. That value is, Be ready. Be primed for opportunity when it shows up, because it will come once, it will move on quick, and if you're not ready to make the shot, your whole destiny can change in a heartbeat."

"Miss that moment, and you'll live the rest of your life wondering just how much of your potential never played out," he continued. "That's when I decided to go from being in good shape to being in the best shape of my life."

In June, ET spoke with the singer at CMA Fest in Nashville, where he offered more details on his health and wellness journey.

"Here's the truth of it -- I was not taking care of myself. I was leaning on the success that I've had," he stated. "My family is counting on me. I want to see my kids grow up, I want to be able to spend time with my grandkids. I want to take them diving and spearfishing, all those things that I want to do with my grandkids."

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