The 'Sleeper Build' meme gained massive traction on social media platforms like TikTok and Instagram within the fitness and bodybuilding communities. Borrowing terminology from the car enthusiast world—where a 'sleeper' is a high-performance vehicle that looks like a standard commuter car—it describes individuals who appear average or slim in loose clothing but possess an impressively muscular or lean physique underneath. The trend typically involves a person posing in a baggy hoodie or shirt before transitioning to a flexed pose, often accompanied by high-energy music. It celebrates the element of surprise and the discipline required to build a physique that isn't immediately obvious until the reveal.