Strengthen Your Core With This Challenging Resistance Band Abs Exercise

Dogpound trainer Rhys Athayde breaks down the move.

When your client A) has an Instagram feed exclusively devoted to her workouts and B) is a Victoria's Secret model who has to exercise as part of her job, it's important to keep things interesting. For a recent training session with Josephine Skriver, Dogpound trainer Rhys Athayde grabbed a resistance band and chose a partner move. The exercise is fitting, since Skriver is half of the fitness duo JoJa with fellow model Jasmine Tookes. The duo posts plenty of partner ab workouts and glutes exercises on their Instagram.

You can check out Skriver and Athayde doing the partner move, via @rjathayde, here:

The move looks intense (in a good way), so of course we wanted a little more detail. We decided to go straight to Athayde to ask him to break down what muscles it works and how to do it right.

This move specifically works the bottom half of your abs, Athayde. Most exercises that involve moving your legs while keeping your core engaged (like this one) put the majority of the work on your lower abs and your hip flexors. That's why it's so important to concentrate on initiating the movement from your abs and squeezing the core muscles tight the entire time.

To do it, start lying down on the ground in a tabletop position with your arms by your sides, while your workout partner loops a resistance band around your feet. (Loop it twice to make sure it's secure.) Engage your core and use your abs to pull your legs toward your face. As you pull and stretch the band, you'll feel the resistance. Then, extend your legs out straight slowly. Your partner should hold the band firmly—a low stance like Athayde's can help them stay stable to be an effective anchor.

"It is crucial to always engage your core throughout the movement," Athayde tells SELF. "[This will help] alleviate pressure on the lower back." He also notes that this is an "advanced exercise that requires a great deal of control over the abs."

If you feel your lower back start to lift off the floor, try using a lighter band. You can also put your hands right under your hip bones to help add a little support. Be sure to communicate to your partner how your body is feeling, and stop and adjust if you need to re-engage your core.

The resistance bands are an update to the classic "partner holding your ankles" sit-ups we've all done in gym class. "[With the bands], you are in full control of how much resistance your muscles can handle, whereas a partner holding your ankles may not understand your strength level or any current injuries you may have," says Athayde. They also let you have total control over your speed.

Athayde suggests adding this move toward the end of a core workout. (That final burner a trainer always makes you do to push out the last of your energy? That's this exercise.) He prefers to work through ab moves like planks and leg lifts, then finish up a session with 15 reps of this move with a 10 second hold on the last tuck. "If you can shoot for 20-25 reps, that's even better!" All you need is a band and a friend who's down to spot you.

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