After hearing about a team going skiing, and Rooney boxing, I got to wondering where to find out about what activities are specifically forbidden in football contracts or club policies? I'd imagine sky diving (which actually is safe) skiing, Dirt bikes, motor sports, Grid Iron football, and if it isn't already on the list it should and that would be horse riding.
Depends on many factors. Different countries have different morals clause rules. It also depends on the sport and the individual contract signed by each individual player. In many ways it is very vague and it is up to the discretion of the company as to what brings bad publicity to them as an organization.
Monday, August 2, 1999 Published at 16:38 GMT 17:38 UK Footballer banned from space Stefan Schwarz: Premiership footballer and Yuri Gagarin wannabe A record Premiership football player has been banned from space travel. Sunderland chief executive John Fickling: "At the end of the day we are protecting the club" "Sunderland's new signing, Stefan Schwarz, has been told he cannot travel into space on one of the first commercial passenger flights - due for lift-off in the year 2002." http://news.bbc.co.uk/2/hi/sport/football/fa_carling_premiership/410156.stm