Commercial or passenger aircraft are usually designed for optimum performance at their cruise speed or VC. Combustion engines have an optimum efficiency level for fuel consumption and power output. Generally, piston engines are most efficient between idle speed and 25% short of full throttle.
The blood to your head rushes when you do a quick movement, so, naturally, dizziness is expected. I think the blood rushes from your head too fast. it is called postural hypotension.. whereby, due to getting up suddenly to a upright position, there is lower blood supply to th head.
Get in a stable position. If you are told to induce vomiting by poison control, sit or kneel for stability. Do not induce vomiting standing up, as vomiting may contribute to instability or jerking body movements. If you are trying to induce someone else to vomit, position them so that their mouth is facing downward. Most importantly, do not induce vomiting in someone that is lying on their back.