We stan a fit couple. Not only are Jennifer Garner and her boyfriend, John Miller, very much in love, but they’re also the epitome of good health. “Jen’s in the best shape of her life and it’s wonderful that she’s got a guy who loves being physically active and is in super shape, too,” an insider revealed exclusively to Life & Style.

As it turns out, the mother-of-three, 46, took major issue with how little ex-husband Ben Affleck paid attention to his physique — which is why John, 40, is such a breath of fresh air. “One of the big turn offs with Ben toward the end of the marriage was how inactive he was,” the insider continued. “He let himself go and lacked motivation, but Jen and John are doing everything from pumping iron to Taekwondo to biking and hiking.”

Jennifer Garner Cute Athleisure Look

“They’re both big body and health nuts and that’s one of the reasons why they’re so hot together,” the source gushed. Hmmm, well, not to shake things up between Jen and her new beau, but her baby daddy, 46, is looking slimmer than ever these days! In fact, Ben recently admitted that her tried out Alex Rodriguez and ex-girlfriend Jennifer Lopez‘s 10-Day Challenge.

“I hate to be shallow about it, but I just did the A-Rod 10-Day Challenge, which I saw on this show, and got inspired by,” he told Hoda Kotb on Today. “I saw Carson Daly bombed out after a day and a half, I said, ‘I know I can get past the donut tray for longer than a day.’” We’re glad Ben stuck with it because he looks fantastic.

“It’s not easy,” he confessed. “I will admit that it was a little bit tough, but I did it … I feel a lot better.” Even if Ben and Jen are no longer together, we can appreciate their commitment to be the healthiest parents they can be!

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