Your goal is to reach the maximum speed possible while relaxed the last few strides to gather for the jump. You also have to hit the board with consistency. A slow start to your run may be justified if that is what you need to get the rhythm to hit the board. But you also need a long enough run to gain the speed and then relax. If you are a good sprinter and jumper, I would think you would need at least 120 feet runup if you start hard. If you are going to start slow, you might need 140' which is hard to come by on some runways. And the longer your runup, the more you might have to deal with fatigue in several jumps. You have to balance the need for rhythm, the need for speed, and the length of your runway. What your coaches say is irrelevant. What you feel, what works for you is what matters. Experiment.
