LONDON (Reuters Health) - A pre-match surge in levels of the hormone testosterone could explain why football teams playing on their home ground are more likely to win, new research suggests. An experiment involving professional football players in the UK showed a 50% rise in testosterone levels before a home game, but no real change before playing at another team's ground or prior to a training session. Researchers from the University of Northumbria said the findings probably reflect a primeval urge to defend home territory against enemy attackers. An increase in testosterone is associated with aggression, confidence and dominance. "There...