Which action is a way to best help remove the personal barrier of eating fast food? Skip eating a meal.
Plan meals ahead of time.
Purchase processed TV dinners.
Eat meals in the car.

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)