I recall Gleatzer riding one of his sub-1min kilos almost 100% with his head down. He swerved like a drunk man in the turns, but it was obvious that keeping the head down as soon as possible through the end was the plan. He didn't look up, only at the boards in front of his wheel.
I would guess that he counted pedal strokes or looked at some marker to know when to expect the turns. Not sure.