Which of the following would be a serious concern from a developmental standpoint? a first grader who had a bathroom accident at school
a second grader who could not cut with scissors
a first grader who cried when she did not win a game
a second grader who could not dribble a ball

The person who utilize the progression principle will keep adding the difficulty of the exercise that he's doing, while the person who does not, will only stay stagnant.  the person that utilize progression principle, will get a stronger endurance because now his body is conditioned to do harsher routines.{the answer was already on verified)