IF you think running beats rope jumping try this
1) double jump for 10 minutes - i bet there is not a single person on this forum who can do 5 minutes let alone 10 minutes, the goal is 20 minutes of continues double jumps - ive never met one boxer in my life who could even do four or five minutes of this let alone 10 minutes.
2) alternative footstep - lifting knees up, no higher than 3 inches of the ground, running in place *this is how it looks* do this for 5 minutes rest 1 minute continue*
3) double jump 20 times, then do alternative footstep for 1 minute, then back to double jumps for a total of 3 minutes
Try work up to 20 minutes of double jumping try get a soft mat to do it on, or good trainers, the impact will be about the same as running in my experience, could be less if you limit the height you jump, this workout beats any any form of running
Never skip like a boxer who bounces on one foot then the other, always rope jump on two feet.