Question

Some people prefer interval training because

Answer 1

The answer is letter D. 

Interval training is usually performed by seasoned or well-trained individuals because of the high demand of speed and degrees of effort needed. Due to the nature of alternating exercise activities within the program, it is preferred by some individuals because it is fast and does not cause boredom. Beginners should not engage in this type of training because of its explosive nature. Through rigorous and a systematic training, beginners can eventually transition to this type of exercise provided that they have been previously cleared because they have already perfected and mastered the form of particular exercises.  

Answer 2

Some people prefer interval training because it's performed with speed and may not cause boredom.