Reply #6: Not just a boxer, but a particularly good one.

[SteppingRazor]

The bodyguard in "The Sign of Four," a man much bigger than Holmes, recalls getting whupped by him in an amateur boxing competition. In another story, Holmes bends an iron bar with his bare hands. He was also a solid fencer and a crack shot.

I'm a big fan of the Holmes works, and while the new movie obviously stresses action, as Hollywood films a re wont to do, I don't think it strays too far from the character, from what I've seen. It just focuses on the more action-hero-like aspects of Holmes' character, which were already present in the original works.