I once travelled all the way from Los Angeles to Boston by train. Took three days. There is no better way to encourage piles than to sit virtually motionless in the same seat for an unnaturally long period. At least when I travelled across Russia some years later I walked around, up and down the corridor mainly. On this occasion, nothing. I could have been an astronaut; except for one function (guess), I lived, slept, ate and drank in one air-conditioned place. But I did change my clothes, though, I got standards.