Pump Up the Healthy Love Episode 6 begins with Mi-ran on a treadmill, obsessing over Joon-seok’s deleted message. She runs too hard and breaks the machine, putting the gym in a financial bind. With no funds for a new treadmill, the staff decides to push personal training with Hyeon-joong to raise money. Even a 30% discount fails to attract interest—until Mi-ran persuades one of the three regular gym ladies, Seong-im, to sign up.

After their victory high five, Hyeon-joong notices Mi-ran’s hands are developing calluses, a sign of dedication. He compliments her and gives her hand cream, putting Mi-ran in a great mood. But when she returns home, she finds her sister Ji-ran crying. Kang Dan broke up with her, claiming that happiness was harming his songwriting. Mi-ran vows to help her sister get over him.

Seong-im’s training with Hyeon-joong begins, and her enthusiasm quickly becomes overwhelming. She’s constantly asking questions, eager to make the most of the gym’s 24-hour access.

Meanwhile at work, Mi-ran learns her Hawaii live show was a hit. Unexpectedly, Ye-jin tells her that it was Joon-seok who recommended her for the opportunity.

Later, Mi-ran brings Ji-ran to the gym. Hyeon-joong, recognizing Ji-ran from their photobooth run-in, tries to keep a low profile. Mi-ran overexerts herself trying to impress her sister, and when she uses unfamiliar equipment, Hyeon-joong covers for her. Elsewhere, Seong-im starts dusting the gym and accidentally breaks Hyeon-joong’s office trophy. On top of that, he realizes he’s losing muscle mass because Seong-im keeps him too busy to train himself.

Seong-im takes Hyeon-joong out for a meal and opens up when she spots her husband with another woman. She asks Hyeon-joong to hide her, and he does. Later, she explains that despite her husband taking her for granted, she doesn’t want a divorce for the sake of their daughter. The gym has become her safe space, and she appreciates the care Hyeon-joong shows.

Back at home, Ji-ran tells Mi-ran that working out helped distract her from Kang Dan. The next morning, Mi-ran tells Hyeon-joong how exercise is strengthening her emotionally too.

Later, Hyeon-joong teaches Seong-im a shoulder relaxation technique. She reflects on how hard it is to let go—especially of family. But while walking outside with her friends, they run into her husband and his mistress. He shamelessly introduces the woman as his colleague and demands Seong-im cook for her. That’s the last straw—Seong-im smacks him in the face with a resistance band Hyeon-joong gave her. Mi-ran helps trip him, and the whole gym squad goes out for drinks afterward.

On their way home, Mi-ran and Ji-ran help a recycling collector. Suddenly, Mi-ran spots Joon-seok approaching and hides. She asks Ji-ran to inquire about the deleted text, which makes Ji-ran realize Mi-ran hasn’t really moved on. Ji-ran, moved, calls Kang Dan and pleads for him to return. Meanwhile, Mi-ran is upset over her missing callus—a sign of her struggle—and ends up crying at the gym with Hyeon-joong.

Pump Up the Healthy Love Episode 6’s epilogue shows Joon-seok watching Mi-ran crying on the street—until Seong-im spots him and accuses him of being a pervert.