Repeat squat jumps are a progression for which of the following exercises?

Repeat squat jumps serve as a progression for the multiplanar jump with stabilization because they incorporate similar movement patterns and require increased strength, power, and control. In a repeat squat jump, the focus is on jumping vertically from a squatted position while maintaining proper form, which develops explosive strength and stability.

In the context of the multiplanar jump with stabilization, the squat jump helps prepare an individual for varying movements in different planes, reinforcing the stabilization necessary when landing and maintaining balance. This is particularly important as the multiplanar jump requires not only the explosive power to leap but also the control and awareness to stabilize after landing.

In contrast, the other choices involve different dynamics or require distinct considerations that do not align as closely with the purpose and benefits of repeat squat jumps. For instance, single-leg hops emphasize unilateral strength and balance separately from the bilateral nature of squat jumps. Vertical jumps focus purely on height and may lack the stabilization component necessary for the progression context of this question. Lastly, box jumps involve an elevation element that shifts the training emphasis towards gaining height and explosive power without the same sustained effort needed in squat jumps.