Cognitive impairment can reduce the person's ability to: receive information from their environment ( the 5 senses )

Cognitive impairment can reduce the person's ability to "process" information in a relatively efficient way, since the person's brain isn't functioning as properly as it otherwise would be. 

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)