Does horse back riding work you harder than motorcycle riding?

I love to do both but wich one works you out harder?? I have my own dirt bike and go to the track and everything, but not very many kids have horses where I live. I would like to sell my quad and get a nother horse but should i do it or not i don't even ride my quad anymore and i still have my yamaha ttr125 but i don't know what to do??