You will have to keep forward and sprint depressed while you crouch under the barriers, otherwise
your stamina will go away very quickly. See this information if you
are having problems crouching while having forward and sprint depressed.
When you crouch, just tap the crouch button and then let go immediately.
The whole time you go around the spiral, you should have your crosshair pointing right around the
front side of the blue glowing cylinder. This jump is probably not possible (or at least
extremely difficult) with 90% health.