"How Heavy Are the Dumbbells You Lift?" centers on Sakura Hibiki, a high school student with a love for food but little interest in exercise. Concerned about her weight gain, she reluctantly joins a local gym after being persuaded by her friend, Ayaka Uehara. At the gym, Sakura encounters Machio, a muscular and knowledgeable trainer who introduces her to the world of fitness. The series explores Sakura’s journey as she learns about various exercises, nutrition, and the importance of maintaining a healthy lifestyle, often with humorous and lighthearted moments.

The narrative balances educational content with comedy, as Sakura and her friends navigate the challenges of working out while juggling their daily lives. Ayaka, a fitness enthusiast, serves as a foil to Sakura’s initial reluctance, while other characters, such as Gina Boyd, a foreign exchange student with a competitive streak, and Akemi Soryuin, a wealthy and eccentric classmate, add depth and variety to the story. Each character brings their own perspective on fitness, contributing to the series’ exploration of different workout routines, diets, and the psychological aspects of maintaining motivation.

The manga incorporates factual information about exercise and health, often presented through Machio’s guidance or humorous interactions between the characters. Topics such as weightlifting, cardio, muscle groups, and proper form are explained in an accessible manner, making the series both entertaining and informative. The plot progresses episodically, with each chapter focusing on a specific aspect of fitness or a new challenge faced by the characters, while maintaining a consistent comedic tone and character development. The blend of humor, education, and relatable struggles with fitness makes the series engaging for readers interested in health and wellness.