Jenna Bush Hager Reveals What Sparked Her Healthy Lifestyle Transformation and Her Go-To Workout (Exclusive)

The 40-year-old 'Today' co-host said it was a 2021 Halloween costume that triggered the workout regimen.

When Jenna Bush Hager's boss told her she had been tapped to dress up as a Dallas Cowboys cheerleader for Halloween, the 40-year-old Today With Hoda & Jenna co-host busted a sweat. Out of nervousness? No way. The sweat was her body's natural way of saying, "Challenge accepted."

On the third anniversary of her Read With Jenna book club, Bush Hager opened up to ET's Rachel Smith about what triggered her healthy lifestyle transformation and, as it turned out, her boss, perhaps unknowingly, lent a helping hand.

"I have to tell you, when your boss says you're gonna be a Dallas Cowboys cheerleader -- and I grew up in Dallas -- guess what? You try to get fit."

Devoted fans of the Today show will remember Bush Hager and Savannah Guthrie (despite being a lifelong fan of the Cowboys' divisional rival Philadelphia Eagles) donned the iconic cheerleader uniform for Halloween last year. Not only did they wear the classic getup, Bush Hager said they also danced with the cheerleaders, which sparked her interest in dance workouts.

Since then, Bush Hager's been on a mission to continue with the pace she's set out for herself while balancing her duties as co-host on a national daytime talk show along with being a devoted wife and doting mother of three.

"I'm continuing," she says of her workout regimen. "It was time. I had three kids. My youngest is two. It's just sort of the progression of getting back into fighting shape."

Bush Hager's workout discipline also translates in the kitchen, where she's mindful of her caloric intake. That being said, Bush Hager's also the first one to admit she's got a soft spot for chips and salsa and a good margarita. Oh, and queso too -- if and when she can find it in New York. Her one advice when it comes to Mexican food?

"Dip the chip in the margarita, people!" she quipped.

Bush Hager, who is from Dallas but lives in New York City, can't train with the Dallas Cowboys cheerleaders but she's found the next best -- though equally as impressive -- option in the Big Apple.

"I have friends who meet me a couple of days a week in my building and I work out with this incredible woman who was a [New York] Knicks dancer," she says. "So, yes. There is dancing. There [are] ab workouts, which frankly [I] did not have an ab before we started doing it, but I found one little ab down in there."

During the same interview, Bush Hager also told ET she's proud of her pal, Hoda Kotb, over how she handled the announcement of her split from Joel Schiffman on the show.

"I am proud of Hoda every single day," Bush Hager said. "She's filled with compassion and grace. I watch her come into her office every morning smiling at every single person."

They'll have even more reason to smile, when Bush Hager and Kotb hit up New Orleans next week for a book festival there.

"She's so excited," Bush Hager said of Kotb. "She gets the thing she loves, which is New Orleans. I get to go to the New Orleans Book Festival for the thing I love, books. We get to do the thing we love together, which is eat and drink."

Chips, salsa and hopefully some queso, too!