What principle refers to tailoring training to the individual capabilities of the athlete?

The principle that refers to tailoring training to the individual capabilities of the athlete is individuality. This concept acknowledges that each athlete has unique physical attributes, skills, and needs, which can vary greatly from person to person. Individuality in training means that programs must be specifically designed to consider factors such as an athlete's age, sex, fitness level, body composition, and previous injuries. This customization helps maximize performance improvements and minimize the risk of injury, ensuring that the training is applicable and relevant to the athlete’s specific circumstances and goals.

The other principles, while important, do not focus primarily on the individual. Specificity relates to training for specific demands of the sport. Progression is about gradually increasing the intensity or difficulty of training. Overload involves doing more than the body currently can handle to stimulate adaptation. Each of these principles supports effective training but does not directly address the unique needs of the individual like the principle of individuality does.