Heh, you can't jump much higher if you have springs of your weight. I jump with +25 kilos exceeding (my weight is 68, my springs are 93, 27% weight exceeding). I can't say I jump mega high - it's about 1,5 meters, but I know guys who jump on +55 kilos! Well... they rule the world!!! But I'm not so trained ((( and can have problems with my spine, neck and knees, if I jump with such an exceeding... Still I want to try.