That sort of repetitive stress is a real concern for all stage actors, along with moving well and making it all look effortless.

FORBES: Bright Lights, Big Fitness: The Business Of Keeping Broadway In Shape

The Milk Cup is now a truly global concern and only the cream of young footballers take the stage.

BBC: SPORT | Football | Irish | Only the cream for Milk Cup

But in this latest stage of the conflict, it is the response of the police that is causing the greatest concern.

BBC: Sao Paulo police at war with prison gang