sit bolt upright

And then write articles arguing that other people should sit bolt upright for hours on end in order to make this choice bearable.

The carriage was a two-wheeled affair, not long enough to permit one to lie at full length nor high enough to sit bolt upright.

One had to sit bolt upright, it seemed, and give this matter one's entire attention.

I pull myself together, and sit bolt upright on the hard wooden pew.

The first few sentences made him sit bolt upright in his chair.

We sit bolt upright round our tables, waiting, but not impatient.