The document discusses the principles of training:
1) Specificity - Training must be specific to the demands of the sport to be effective. For example, a goalkeeper would focus on reaction training while a runner would work on leg strength.
2) Overload - To improve, training must place greater demands on the body than normal. Weightlifters aim to train at 60-80% of their maximum to gain strength.
3) Progression - Training needs to gradually increase over time to continue providing improvements. A runner increased his session length each week to progressively challenge himself.
4) Reversibility - Fitness is lost faster than it is gained if training stops. Athletes must continue training to maintain their