'Swolemates' Jessica Biel and Justin Timberlake Just Ended 2021 with a Fierce Ab Workout

Jessica Biel and Justin Timberlake just proved that the couple who sweats together, stays together... but once you see the pair's intense joint ab workout, you'll understand why these two look utterly breathless at the end of their core circuit.

Posting a shared Instagram video from both of their accounts, Biel and Timberlake captioned the clip, "Swolemates. See you in 2022 🙌🏻." And judging by their end-of-year sweat session, no one is ready to tackle the new year quite like this duo, who made a series of mat-based core moves look effortless — despite the fact that they clearly had to dig deep get it done.

Working together on the same mat (aw, how sweet!), the pair began by doing plank walk-ups, remaining in perfect plank form as they moved each hand forwards and backwards on the floor. They then moved into plank hip dips, switching to a forearm plank before lowering their hips on each side with control — no easy feat, as you've got to maintain strength from shoulders to toes to prevent injury. Biel even took an exasperated breath before moving into the next move, and when you watch it, you'll fully understand why.

Next up: plank shoulder-taps, which involve keeping your body in solid plank form as you alternate tapping each shoulder with your hands individually. It requires tons of control to prevent your hips from swaying, as well as strength throughout the upper body, core, and lower body to hold yourself up while you're switching hands. (Are you sensing a theme yet?)

They followed that up with an even more intense full-body move: a forearm side plank with the other arm held straight in the air, with the couple upping the ante by adding a knee drive with the top leg. Timberlake looked particularly pained by this one, gritting his teeth before the pair switched over to complete the move on the other side. (ICYDK: Side Planks Are Basically the Best Obliques Exercise Ever)

At the end, Biel smiled widely as the *NSYNC alum dropped to his knees to rest — all the signs of a successful workout, indeed. Back in 2018, the actress told Self that the couple, who got married in 2012, always try to squeeze in a joint workout when they can.

"I actually love mommy-daddy workouts, they're the best," she said at the time. (Biel and Timberlake have two sons: Silas, 6, and Phineas, 1.) "It doesn't always happen, but it's so nice to have a partner when you're doing a workout. It's something my husband and I really enjoy doing together — we both are workout enthusiasts. When we can, we make it happen." (Real talk: Having a fitness buddy is the best thing ever.)

It seems that they both enjoy mixing things up in the gym, with the actress adding, "We'll work with a trainer and just do different circuits and do different types of cardio training or sprinting, just different things depending on what we're working on and goals we're trying to hit at the time." Biel also mixes things up on her own, whether she's following the lead of the couple's go-to trainer, Ben Bruno (who also trains Kate Upton and Chelsea Handler), by crushing skater squats with a twist or plyo box pistol squats with dumbbells... or practicing at-home yoga on her own. As she told Shape in 2018, the practice completely changed her relationship with fitness and allowed her to reconnect with her body and mind. (Read more about Biel's love of yoga here.)

As for Timberlake, he doesn't come to play in the gym either, frequently working with Bruno to prepare for roles and boost his full-body strength all the time.

TBH, if you have FOMO over the couple's fierce fitness routine, you can always give it a try on your own — though, to be fair, those core moves are not for the faint of heart. You've been warned.