Her trainer told us her go-to move. 

Blake Bakkila
July 27, 2018

Jennifer Lopez’s post-birthday festivities are looking abs-olutely stunning. On Thursday, the 49-year-old star shared a photo of herself lounging on the beach in a black bikini.

“Island vibezzz…” she captioned the image.

Island vibezzz... 🏝 #vacaciones

A post shared by Jennifer Lopez (@jlo) on

This certainly isn’t the first time she’s shown off her toned tummy. In fact, she wore the same suit in a group photo with family and friends earlier this week. “Current birthday situation… yup,” she wrote.

Current birthday situation... yup photo credit : @lacarba

A post shared by Jennifer Lopez (@jlo) on

While we don’t have the secret to an epic birthday celebration like J.Lo’s, we can tell you more about how she builds muscle in her abs. Last November, her trainer, David Kirsch, shared with Health the one move she relies on: side-plank oblique crunches.

RELATED: Why the $92 Leggings J.Lo Swears By Are Worth the Splurge

"It’s perfect for when you need to focus on shaping and toning not only the obliques but the entire core," he said.

Of course, that’s not the only exercise the entertainer does during her sessions with Kirsch. Last year, he shared this video of Lopez doing a series of sit-ups with a medicine ball.

"I love to keep workouts with Jennifer high energy and high intensity, making sure the full-body workouts are fresh and always changing," Kirsch previously told Health.

What we love even more than J.Lo’s abs, however, is her easygoing attitude about approaching the end of her 40s and aging in general. “Listen, at some point, I’m going to age,” Lopez joked in an interview with Emmy magazine. “They’ll say, She looks old! But, right now, I’m holding it together.”

Whether her looks start to change or not, we can all appreciate that she’s still Jenny from the block and keeps her attitude real.