The FITT cycle stands for: 
Frequency: the number of times you perform an exercise in a workout session/week 
Intensity: How hard you practice, or the amount of energy you put in a workout session. There are three levels: low, medium and high intensity workouts 
Time: For how long you are performing an exercise (time duration) 
Type: what kind of exercise you are performing (yoga, cardiovascular, strength training etc.) 
The FITT cycle can be applied to any workout regime.