Training for a marathon has given Chip Gaines some serious, well, gains. The Fixer Upper star is just one month away from completing his first-ever marathon, the Silo District Marathon in Waco, Texas. And he’s sharing his new fitness goal (and weight loss!) on Instagram.

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In a photo posted to the Gaines family’s @magnolia account, a beaming, fist-pumping Chip is racing along a trail. Just last month, the 43-year-old father of four (and soon-to-be five!) talked to Runner’s World about how running has changed him physically and mentally.

“I’m down around 10 pounds!” he said in the interview. “And the fact that I’m not sucking wind at mile 1 is probably a pretty good sign, too.”

Gaines explained that he’s sacrificed some sleep during his grueling training schedule, but his family has been the ultimate support system. In one adorable post he shared in January, Chip showed his followers the pre-run snacks and motivational notes his little ones prepared for him.

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“It’s about making a commitment and sticking to it no matter what,” he wrote. “And trust me, that ‘no matter what’ part is a real kick in the pants…especially at five o’clock in the morning. But my family is so supportive of this whole thing—my kids are excited for me when I leave on a long run, and they can’t wait to ask me how it went when I get back. If anything, they’re helping me hold myself accountable.”

And while his newfound love of running is changing his looks, the TV star’s natural confidence has remained solid. Last May, he talked about his pre-weight loss “dad bod” in the summer issue of The Magnolia Journal.

“At any given moment, there’s a little voice in my head . . . that’s constantly telling me, ‘Way to go, Chip, that was so funny!’ and ‘Hey, Chip, you look good in that size medium T-shirt!’ A few times [it] has even told me my dad bod is ‘rockin.’”