I punched a woman during a karate class once. It was the most awful thing ever. She stepped forward into what was supposed to be a fake punch, and whammo, right in the solar plexus. :'( She doubled over and didn't get up for about 5 mins. Meanwhile, I have a roomful of her angry black-belt chums frowning at me. I could barely speak Japanese at the time so my apologies may not have been the most appropriate either.