A principle of training dictating that overload should be increased gradually during the course of a physical fitness program is the:

progression principle

Explanation:

A principle of training which indicates that dmoverload should be increased gradually during the course of a physical fitness program is refered to as the progression principle.

According to this principle, when doing an exercise, it should be started slowly and then gradually increased. The progression can be over a couple of weeks or months.

for question 8

1: it gets the blood pumping more

2: endorphins and other neurotransmitters

i think it would be b the increase in body temp