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.
