Including strength training in a fitness plan is significant for numerous reasons. It helps build and maintain muscle mass, which naturally declines with age, thereby supporting metabolic health. Strength training also enhances joint stability and functionality, reducing the risk of injuries. Additionally, engaging in regular strength workouts can improve body composition by increasing lean mass and aiding in fat loss. Importantly, it boosts overall strength and endurance, enhancing performance in daily activities and sports. Thus, incorporating strength training is essential for a well-rounded fitness regime.