Cone hops are great for developing reactivity. The two legged version is easier than the single leg, but none the less is also an excellent exercise for developing ankle strength.
The emphasis on all reactive exercises is to land, stabilize and absorb the landing forces, and then explode back off the ground quickly. This is no different. Jump back and forth over the cone (or in the case of the video the sand bag - really anything can be used) trying to minimize ground contact time and maximize jump height.
Cone hops are a nice vertical jump training exercise for sure, but if you are after results that are truly off the charts you need to check out or one of kind jump training book Game Changers. This book contains vertical jump training techniques you won't find anywhere else that produce results unlike anything else.
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