Answer:
Overload
Step-by-step explanation:
Also known as the principle of progressive lifting of the load, the principle of overload is related to the adaptations suffered by the organism as a result of the training stimuli (physical effort). In this principle there is a regular and progressive increase of the (total) exercise load that will allow the desired improvement of performance. Based on this principle, Anthony struggled to lift heavier weights than the weights he was lifting. This is because it is progressively increasing the exercise load. For that reason, he felt good, but his muscles were sore because they were not used to this weight.