Actress Jordana Brewster is perhaps best known for her role as Mia Toretto in the Fast and the Furious movie franchise. But when it comes to her workouts, she’s not fast and furious—she’s patient and determined. Earlier this week, Brewster re-grammed trainer Harley Pasternak‘s post of her doing an assisted pull-up at the gym, and Pasternak called out the actress for her long-term dedication.
“Very proud of the incredible physique our client [Jordana Brewster] has honed after 10 [years] of work together. A big focus of our training has been on her posterior chain,” the caption read. “She’s worked very hard on strengthening the back of her body, and it really shows!”
“The assisted pull-up works the lats [latissimus dorsi] mainly, and the biceps to a lessor extent,” Pasternak tells SELF. Your lats are the wide back muscles located near the bra-strap area, and they’re one of the largest muscle groups in the body. According to the trainer, the lats are “a very powerful trunk rotator” that play a role in lifting your arms up or down (as in a pull-up) or forward and back (as in a fly). The muscle is especially important in sports such as swimming and rowing.
There’s a practical reason for firming up your lats, too. So much of our daily lifestyle is spent indoors, usually sitting, Pasternak says. Whenever you’re sitting, your torso is in an elevated position. If the muscles that keep your torso upright are weak, though, “This leads to poor posture and prevalence of neck, shoulder, and back pain,” he says. The fix? Strengthen the muscles that help keep you upright, including the lats, and your posture won’t fall apart at the end of a long day. “The lat muscles help pull everything down,” he adds.
In the Instagram post, Brewster is using a piece of equipment specifically designed for assisted pull-ups, called the Total Pull Up by Total Gym. If you don’t have access to specialized gym equipment, it’s relatively easy to perform a similar move at home using a resistance band, Pasternak says. Simply anchor the middle of the band above your head (shut it in a secure doorframe or loop it around a sturdy beam), grab the handles with your palms facing out, and pull the handles down toward your shoulders; pause, then return your hands to the start position. (Watch a full tutorial on how to do a resistance band pulldown here.)