Dance, is it a sport?

[A l e x x (L)]

i am a confident dancer, i do some form of dance everyday. Alot of the time i feel i put in more effort in an hour than any footballer or rugby player would in a match, but yet Dance isn't classed as a sport. Dance takes training, a certain level of fitness, practice, key skills, and you have tournaments/competitions just like any other sport. This is a current arguement with a very close boy mate of mine who is a rugby player and i feel i must prove him wrong, anyone back me up?
Thanks x