Olympic athletes aren't known for being shy and retiring - but some of the sportsmen and women let their troubles get to them more than others.
For a man not known for his smile, Great Britain's Andy Murray is one of London 2012's most expressive athletes when it comes to beating himself up.
But it's Germany's Markus Steuerwald, pictured above, who has pulled the toughest pouts in the tournament so far, during his volleyball match against Serbia.