For decades, fitness culture treated cardio as the foundation of health—measured in miles run, calories burned, and hours spent chasing endurance. But a growing body of research is changing that conversation, placing strength training at the center of long-term health and aging. In this episode, we explore the cultural and medical shift toward building muscle as a form of prevention, tracing how resistance training moved from the gym subculture into mainstream public health advice. From protecting against frailty and falls to supporting metabolic health and independence later in life, we examine why muscle may be one of the body’s most important defenses against aging. The story reveals a new understanding of fitness, where strength is no longer just about appearance or athleticism—but about preserving the ability to live well for as long as poss ...