Bestselling author and former competitive swimmer Bonnie Tsui reflects on the meaning of muscle and what exercise and movement bring to our lives.

Over the past few decades, the toned, superhero physique has become the new ideal of physical strength and beauty. Weightlifting, which used to be a niche interest in the world of fitness and competitive sports, has entered the mainstream.

While lifting heavy might be a passing fitness trend, our muscles have always allowed us to move, work, play, and have a sense of agency in the world.

Bonnie Tsui is an American author, New York Times contributor, and former competitive swimmer, known for her bestselling memoir Why We Swim.

In her 2025 book, On Muscle, Tsui explores the meanings that muscle carries in society and how movement and exercise reflect our physical and mental capabilities.