What aspect of fitness does the term 'muscle overload' refer to?

The term 'muscle overload' refers specifically to the practice of challenging muscles beyond their current capacity. This principle is essential for muscle growth and strength development, as it encourages the muscles to adapt to greater levels of stress. When you expose muscles to higher tension through heavier weights, more repetitions, or varied exercises, they respond by growing stronger and increasing in size. This concept is foundational in resistance training and is critical for anyone looking to improve their physical fitness, as it stimulates muscle fibers to repair and build up, leading to enhanced performance over time. The focus on progression, such as increasing resistance or intensity in workouts, effectively keeps the body adapting and improving.