The best way to get through high rep burpee box jumps is pacing. To pace them, you need to have consistent foot work. If you are adding extra steps to your movement, you are leaking energy. When some of your reps are faster than others, you will be forced to rest more than you really want. The middle of this workout doesn't need to be fast, it just needs to be done. You can pick up the pace on the last run.