3(a) .Exercise is often described as training and should include:
A. Exertion of the lungs.
B. Exertion of the heart.
C. Exertion of the muscles
D. All of the above.
3(b). Muscular endurance is defined as:​

Exercise is often described as training and should include All of the above.

Thus, option D is correct.

The capacity of a muscle a particular muscle grouping to sustain repeated spasms against such a force over a protracted period of time is referred to as muscular endurance. The more repetition someone could perform, the stronger their muscle endurance was.

Exercises are often defined as training processes. Therefore this would need a full body workout if possible, exercise should be of different parts. It should not only concentrate on muscles but also on lungs and hearts.

Therefore exercising the whole body is important and training at would also imply that it would be good in the long run for a person's body

Therefore, option D is the correct option.

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