What does the overload principle state?

The overload principle states that in order to improve physical fitness and performance, the body must be subjected to greater than usual demands. This means that for muscles to grow stronger or for overall fitness to improve, the intensity, duration, or frequency of exercise needs to be increased beyond what the body is accustomed to. Gradually increasing these demands forces the body to adapt, leading to improvements in strength, endurance, and overall fitness.

This principle is foundational in designing training programs, emphasizing that simply maintaining the same level of activity will not lead to further adaptations or progress. By purposefully increasing the workload—whether by lifting heavier weights, increasing the number of repetitions, or extending workout duration—individuals can stimulate muscle fibers and cardiovascular systems, prompting them to adapt and improve.

The other options suggest different strategies that do not align with the fundamental concept of the overload principle. For example, resting more or eating more does not inherently lead to increased fitness unless it is part of a greater strategy of managing workload and recovery. Training at low intensities does not apply the overload principle, as it does not push the body beyond its current capabilities to drive adaptation.