For those who want to keep fit, the effect of alternating multiple physical exercises is better than that of a single project.A single project of exercise makes a small number of muscles developed, while the alternating multiple physical exercises can develop the body's muscle group in an all-round way, and the latter consumes more calories than the former.
If it is much more difficult to fully develop the muscle group of the human body than to promote the development of a small number of muscles, then this option most advantageously reinforces the above argument.