size of exported animation video is always the same and very big

Whenever I create an animation in PTC Creo Parametric it is always the same size. It does not matter if I do it with rendered shots or not. For example, for my 10 seconds animation it is round about 1.5 Gigabytes.

That is a lot. In my opinion Creo must store a lot of unecassary information. Does somebody know how to reduce this size? Why is it always the same size? I am exporting with 25 fps on Creo 8.0.4.0