principals of weight training, progression is the act of gradually adding to the amount or type of stimulus applied to the muscle during each exercise.
Without consistent progression in your workouts, you wont overload your muscles sufficiently to promote optimum increases in hypertrophy (muscle size), strength and endurance. Progression can be achieved by continuously changing the stimulus applied to the muscle.
These changes can include progressively increasing the weight used during an exercise, the total amount of work performed (volume and reps), time that the muscle is under tension (tempo), frequency of training, and the introduction of additional exercises or variations on the exercise performed.
