D 1. What FITT principle refers to the difficulty or exertion level of your physical activity or exercise?
Frequency
Intensity
Time
Type

Respuesta :

Answer:

Intensity

Explanation:

This refers to how hard the work is performed. This can be affected by many different factors such as amount of resistance or weight used, the speed or power exerted, changes in the sets and reps, amount of rest time, etc.