Is Foam Board Insulation Strong Enough To Be Placed Over Floor Joists And Then Install A Floor Over It?

I am going to be building a 10×14 shed when it warms up a bit. I plan to use it as a shed to store my lawn tractor and garden tools but i can see a time in the future where i may want to use it as an escape (i am going to run power, tv and internet to it). I can insulate walls and ceiling later but the floor is something i think is a lot easier when you are building the shed. My first thought...