Episode 1 of "Pump Up the Healthy Love" kicks off with Do Hyeon-joong getting dumped by his girlfriend, who cites his singular focus on fitness as the reason. The narrative then shifts to him triumphantly winning a bodybuilding competition, collecting his prize, and nonchalantly exiting the stage. He ultimately returns to Seoul, where he's seen distributing flyers. Alongside his colleague, Alex, they witness Mi-ran, a woman, engaged in a heated altercation with her boyfriend, Joon-seok, outside a motel. Tears streaming down her face, she pleas with him to share intimate moments with her, but he leaves her behind. In the aftermath, Hyeon-joong offers Mi-ran a flyer promoting his club.
The scene transitions to glimpses from Mi-ran's tumultuous past, painting a picture of her persistent misfortune in the realm of love and romance. Returning to her residence, she's initially delighted to find it adorned with balloons and sweet notes. However, her joy quickly turns to shock when she discovers an unfamiliar man in her bedroom. In a bid to confront him, she chases him into the streets but finds herself unexpectedly getting arrested. At the police station, the man reveals himself to be the boyfriend of Mi-ran's sister, Ji-ran, who shares the same house.
Once the confusion is cleared up, the young couple returns home, leaving Mi-ran to drown her sorrows in alcohol. Amid her despair, she hallucinates a woman in an advertisement, reminding her of the flyer tucked in her bag. She retrieves it and sets off for the location, mistakenly believing it to be a nightclub. presents her with a Total Life Care package worth five million won, promising to make it happen in three months. She rejects him outright, accusing him of body-shaming, and storms off.
We then gain insight from Rosa, the gym's diligent proprietor, that since Do Hyeon-joong's arrival, the atmosphere has taken a turn for the worse. His abrupt and unfiltered manner of speech alienates the clientele. Amidst a chat among three female patrons, we discover that Director Dong, Rosa's father, once helmed the gym and took in Hyeon-joong as an orphan. Nowadays, Hyeon-joong is an ever-present figure at the gym, his life revolving around its walls. While he is immersed in his workout, three nightclub proprietors interrupt him, accusing him of encroaching on their territory by distributing flyers. With ease, he outmaneuvers them, drawing them into a session of exertion.
Back at her abode, Mi-ran ponders whether Joon-seok's heated words during their argument signaled the end of their relationship. Her supportive sister urges her to confront him directly. Heading to work, we learn that Mi-ran and Joon-seok share the same office space. To her surprise, Joon-seok announces his impending transfer to South America. Mi-ran corners him, and he formally terminates their relationship, citing her as too deserving for someone like him. She persists, once again inquiring why he refrained from sharing a more intimate connection with her.
At the gym, the landlord threatens eviction, targeting Hyeon-joong and his companions. In a bid to persuade him otherwise, Hyeon-joong enumerates his impressive array of victories and accolades. Rosa too harbors uncertainties about the gym's future. Just as tensions escalate, Mi-ran bursts in, handing over 5 million won to enroll in Hyeon-joong's comprehensive Total Life Care program. A flashback reveals Joon-seok's harsh admission to Mi-ran that her physical form hindered their intimacy.
In the present, Hyeon-joong assures Mi-ran that her life is poised for transformation. As she exits, a chance slip sends her tumbling into his reassuring embrace. The epilogue of Pump Up the Healthy Love Episode 1 finds Joon-seok striding away after his hurtful comments to Mi-ran, only to bump into Hyeon-joong, resulting in a clumsy fall. Hyeon-joong implores him to cease deflecting responsibility and embrace honesty.
