Friday is Kate Middleton's 33rd birthday! Kate knows a thing or two about following proper royal protocol and maintaining perfect poise during official appearances, but she's also not afraid to work up a sweat. Kate's been active since Saint Andrew's school, where she played tennis and swam, and her sporty days haven't stopped since she became a duchess. She showed off her athletic skills in front of the cameras during her royal tour of New Zealand and Australia  in April, so we rounded up all of her most active moments (remember that cricket game ?).