Drugs that affect the central nervous system, such as sedative/hypnotics, are dangerous to use when driving because

It's dangerous because the brain uses information received by the nerves which coordinate your actions and reactions.

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)