How much of conditioning is genetic?

did you misinterpret the weight?

 

I gave the benefit of the doubt that it was a typo until the last post by the OP. 20-40% is the optimal percentage you want for this. Gradually increase your work time and decrease the rest time over the weeks, and I'm referring to 2 secs increase in work and 5-10 secs decrease in rest time over several weeks. Start easy, say 10 secs of work and 50-60 secs rest. Also, you don't use reps, use time.

You are attempting to make the Type IIA fibers more oxidative in nature, and are training for that adaptation, or said another way, training to sustain explosiveness for longer and more often. The idea is to be able to do rebound jumps in succession.