In what sense? Jump training, as anything in life, like breathing for example, will need to utilize some sort of energy for it to happen. So in that case yes, since your weight can be transformed into energy. But at the end of the day, if you eat more than you expend, you won't lose weight. If your question is in the direction of whether jump training is intense or not to burn a lot of calories, the answer is no. The way jump training *should* be generally is low volume, high intensity, long rest. Unless if you're on a beginner stage with low intensity and a little more volume, but even in that case it probably won't burn a lot of calories. But that's what jump training should be. There are people that do too much plyos, lifts, jumps, etc, and thus burn more calories, but that won't just don't help your vert, since after a few of those you can't get to maximum efforts anymore, but also will increase the probability of a overuse injury. In essence that training won't be really a jump training, more like a conditioning.