The repeated bout effect refers to the body’s adaptive response to exercise. When you engage in a novel activity that your muscles aren’t accustomed to, it often leads to muscle soreness and damage, known colloquially as Delayed Onset Muscle Soreness (DOMS). This is especially common after eccentric loading, starting a new program, or following a break from training. When you repeat the same exercise after your muscles have recovered, you’ll notice reduced soreness due to several adaptations within the muscle. These adaptations include neural adjustments (improved coordination and muscle recruitment), mechanical changes (increased tendon stiffness and muscle strength), and cellular modifications (enhanced repair processes and alterations in muscle protein synthesis). These changes contribute to the muscle becoming more resistant to damage over time. Essentially, your muscles have learned from the previous experience and have adapted to handle stress more effectively. As muscles adapt...