Estefan has determined his bmi at 31. explain how he can apply the fitt training principles to improve his body composition.

Frequency:

Cardio : Five or more 
HIIT: 5 or 4

Strength: 2-3 days on non-consecutive days a week
 
Intensity:
How hard you work during the session

For cardio : workout at your target heart rate.
For HIIT: varying intensity from high to low or rest ( no slow pace)
For strength: you should lift enough weight to complete the needed number of reps and sets.

Time:

For cardio 30- 60 min
For HIIT 45 min (short periods of bursts followed by rest)

For strength depends on the amount of weight.

Type:

Either cardio, HIIT or strength training (resistance training) 

NOTE: This info is given by an unqualified brofessor, who uses his hard gained bro-science in the expense of scientific facts to solve others broblems.