The belief that thinner runners are inherently faster is a harmful myth that oversimplifies the complexities of performance. While lower body weight can improve running economy, overemphasis on weight often leads to disordered eating, weakened bodies, and a disregard for individual potential. True speed comes from factors like VO2 max, efficient biomechanics, consistent training, and mental resilience—not from chasing a specific weight. Elite athletes like Yuki Kawauchi and Courtney Dauwalter prove that strength, consistency, and grit trump body type. Run to build a strong, healthy body—not to conform to a stereotype.