Which training principle focuses on gradually increasing the volume of training over time?

The principle that emphasizes gradually increasing the volume of training over time is known as progressive overload. This principle is foundational in exercise and physical training, as it posits that to achieve continued improvements in strength, endurance, and overall fitness, an individual must consistently challenge their body by increasing the demands placed upon it. This might involve lifting heavier weights, increasing the number of repetitions or sets, increasing training duration, or enhancing the intensity of workouts.

The essence of progressive overload lies in the concept that the body adapts to a certain level of stress or training stimulus. Once it adapts, in order to continue on the path of improvement, the stimulus must be elevated. This gradual increase is critical for making gains, preventing plateaus, and reducing the risk of injury by allowing the body to adapt safely over time.